(19)
(11)EP 3 124 146 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
24.06.2020 Bulletin 2020/26

(21)Application number: 15768527.2

(22)Date of filing:  27.03.2015
(51)International Patent Classification (IPC): 
C23C 14/06(2006.01)
C23C 28/00(2006.01)
C23C 28/04(2006.01)
C23C 30/00(2006.01)
(86)International application number:
PCT/JP2015/059553
(87)International publication number:
WO 2015/147241 (01.10.2015 Gazette  2015/39)

(54)

COATED TOOL

BESCHICHTETES WERKZEUG

OUTIL REVÊTU


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 27.03.2014 JP 2014064910

(43)Date of publication of application:
01.02.2017 Bulletin 2017/05

(73)Proprietor: Tungaloy Corporation
Iwaki-shi Fukushima 970-1144 (JP)

(72)Inventors:
  • HIRANO, Yusuke
    Iwaki-shi Fukushima 970-1144 (JP)
  • METOKI, Kenji
    Iwaki-shi Fukushima 970-1144 (JP)

(74)Representative: Vossius & Partner Patentanwälte Rechtsanwälte mbB 
Siebertstrasse 3
81675 München
81675 München (DE)


(56)References cited: : 
EP-A1- 2 700 460
WO-A1-2014/025057
JP-A- 2010 099 769
JP-A- 2011 104 687
US-A1- 2009 155 559
WO-A1-2008/146727
WO-A1-2014/025057
JP-A- 2010 188 461
JP-A- 2011 104 722
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    TECHNICAL FIELD



    [0001] The present invention relates to a coated tool.

    BACKGROUND ART



    [0002] In recent years, cutting with high efficiency has been highly demanded. Accompanying with heightening of this demand, a cutting tool having a longer tool life than that of the conventional ones has been required. Thus, as characteristics required for the tool materials, it is important to improve characteristics relating to lifetime of a cutting tool. For example, it is more important to improve wear resistance and fracture resistance of the cutting tool. To improve these characteristics, a coated tool wherein alternately laminated films in which coating films are alternately laminated are formed on a substrate has been used.

    [0003] To improve characteristics of such alternately laminated films, various techniques have been proposed. In Patent document 1, for example, a cutting tool in which a specific metal element or a compound thereof, and a specific alloy compound are laminated onto a surface of a base material with laminating cycles of 0.4 nm to 50 nm has been proposed. It has been disclosed that the cutting tool shows excellent wear resistance.

    [0004] In Patent document 2, a cutting tool in which a first layer and a second layer are alternately laminated on a substrate so that these layers become 4 layers or more has been proposed. The first layer contains a complex nitride represented by the compositional formula of (Ti1-XAlX)N (X: 0.30 to 0.70 in an atomic ratio). The second layer contains an aluminum oxide phase and a titanium nitride phase. A ratio of the aluminum oxide phase in the second layer is 35 to 65% by mass based on the total of the aluminum oxide phase and the titanium nitride phase. Average thicknesses of the first layer and the second layer are each 0.2 to 1 µm. An average thickness of the first layer and the second layer in total is 2 to 10 µm. It has been disclosed that the cutting tool has excellent wear resistance.

    [0005] In Patent document 3, a coated tool containing a first laminated structure and a second laminated structure has been proposed. The first laminated structure has a structure in which two or more layers having different compositions are periodically laminated. The average thickness of the respective layers contained in the first laminated structure is 60 nm or more and 500 nm or less. The second laminated structure has a structure in which two or more layers having different compositions are periodically laminated. The average thickness of the respective layers contained in the second laminated structure is 2 nm or more and less than 60 nm.

    PRIOR ART DOCUMENT


    PATENT DOCUMENT



    [0006] 

    Patent document 1: JP Hei.7-205361A

    Patent document 2: JP 2003-200306A

    Patent document 3: WO 2014/025057A



    [0007] Document EP2700460 A discloses a coated cutting tool having a coating made of alternating stacked layers. A similar tool is described in the document US2009/155559 A.

    SUMMARY OF THE INVENTION


    PROBLEMS TO BE SOLVED BY THE INVENTION



    [0008] In recent years, high speed, high feeding and deep cutting in a cutting process becomes more remarkable. Thus, fracture of the tool has been frequently generated. For example, due to the load applied to the cutting edge during the processing, cracks are generated at the surface of the tool. By propagating the cracks to the substrate, fracture of the tool is generated. In addition, if a temperature of the cutting edge is rapidly raised or lowered, cracks are generated at the substrate. By propagating the cracks to the coating layer, fracture of the tool is generated.

    [0009] According to such a background, the cutting tool disclosed in the above-mentioned Patent document 1 has high wear resistance, but has a problem that facture of the tool is likely generated. The cutting tool disclosed in Patent document 2 has a problem that wear resistance is poor since hardness of the film is insufficient. The cutting tool disclosed in Patent document 3 cannot fulfil the required properties since fracture resistance is insufficient.

    [0010] The present invention has been done to solve these problems. An object of the present invention is to improve fracture resistance without lowering wear resistance of a coated tool. In addition, an object of the present invention is to provide a coated tool having long tool life.

    MEANS TO SOLVE THE PROBLEMS



    [0011] The present inventors have intensively researched on elongation of tool life of a coated tool. The present inventors have accomplished improvement in fracture resistance without lowering wear resistance of the coated tool by improving a constitution of the coating layer. As a result, tool life of the coated tool could be elongated.

    [0012] That is, the present invention is defined by the claims.

    EFFECTS OF THE INVENTION



    [0013] The coated tool of the present invention is excellent in wear resistance and fracture resistance, so that it can accomplish the effect that tool life can be elongated than those of the conventional ones.

    BRIEF DESCRIPTION OF THE DRAWING



    [0014] Fig. 1 is an example of a schematic drawing of a cross-sectional structure of the coated tool of the present invention.

    EMBODIMENT TO CARRY OUT THE INVENTION



    [0015] The coated tool of the present invention comprises a substrate and a coating layer formed onto a surface of the substrate. The substrate of the present invention may be any material so long as it is used as a substrate of the coated tool. The substrate of the present invention is not particularly limited and may be, for example, a cemented carbide, cermet, ceramics, a cubic boron nitride sintered body, a diamond sintered body and high-speed steel. Among these materials, a cemented carbide is preferred. This is because the cemented carbide is excellent in wear resistance and fracture resistance.

    [0016] In the coated tool of the present invention, an average thickness of the whole coating layer is preferably 0.22 to 12 µm. If the average thickness of the coating layer is less than 0.22 µm, wear resistance of the coated tool tends to be lowered. If the average thickness of the coating layer exceeds 12 µm, fracture resistance of the coated tool tends to be lowered. The average thickness of the whole coating layer is further preferably 1.0 to 8.0 µm.

    [0017] In the coated tool of the present invention, the coating layer contains a specific first laminated structure and second laminated structure. The respective layers contained in the first laminated structure and the second laminated structure contain a compound comprising at least one metal element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Sr, Y, Sn and Bi, and at least one non-metal element selected from the group consisting of carbon, nitrogen, oxygen and boron. The coated tool of the present invention is excellent in wear resistance.

    [0018] The layers contained in the first laminated structure and the second laminated structure more preferably contain a compound comprising at least two kinds of metal elements selected from the group consisting of Ti, Nb, Ta, Cr, W, Al, Si, Sr and Y, and at least one non-metal element selected from the group consisting of carbon, nitrogen, oxygen and boron. This is because such a compound has a property of being hard. The compound contained in the layer constituting the first laminated structure may be specifically (Al0.50Ti0.50)N, (Al0.60Ti0.40)N, (Al0.67Ti0.33)N, (Al0.67Ti0.33)CN, (Al0.45Ti0.45Si0.10)N, (Al0.45Ti0.45Y0.10)N, (Al0.50Ti0.30Cr0.20)N, (Al0.50Ti0.45Nb0.05)N, (Al0.50Ti0.45Ta0.05)N, (Al0.50Ti0.45W0.05)N, (Ti0.90Si0.10)N, (Al0.50Cr0.50)N, etc.

    [0019] The metal element(s) contained in the layer constituting the first laminated structure is/are preferably the same as the metal element(s) contained in the other layers constituting the first laminated structure. That is, a plurality of the layers constituting the first laminated structure are preferably constituted by the same kinds of the metal elements. In addition, it is preferred that an absolute value of the difference between a ratio of the specific metal elements contained in a layer constituting the first laminated structure and a ratio of the specific metal elements contained in the other layer constituting the first laminated structure adjacent to the above layer is 5 atomic % or more. "A ratio of the specific metal elements" herein mentioned means a ratio (atomic %) of the number of the atoms of the specific metal elements contained in the layer based on the number of atoms of the whole metal elements contained in the layer.

    [0020] If the first laminated structure employs such a constitution, crystal lattice becomes inconsistent at the boundary surface between the layers without lowering adhesiveness between a layer constituting the first laminated structure and a layer adjacent to the layer. Therefore, cracks are likely propagated to the direction parallel to the boundary surface of the layers constituting the first laminated structure, whereby propagation of the cracks to the substrate can be effectively suppressed.

    [0021] With regard to the above-mentioned "absolute value of the difference between a ratio of the specific metal elements contained in a layer and a ratio of the specific metal elements contained in the other layers adjacent to the above layer is 5 atomic % or more", it is explained in more detail.

    [0022] For example, when the first laminated structure is constituted by an (Al0.55Ti0.45)N layer and an (Al0.67Ti0.33)N layer, the kinds of the metal elements contained in the two layers are the same. This is because the two layers both contain Al and Ti. In this case, the number of the atoms of Al contained in the (Al0.55Ti0.45)N layer is 55 atomic % based on the number of the atoms of the whole metal elements. The number of the atoms of Al contained in the (Al0.67Ti0.33)N layer is 67 atomic % based on the number of the atoms of the whole metal elements. The difference in the ratios of the numbers of the atoms of Al in these two layers is 12 atomic %. Accordingly, in this case, the above-mentioned condition that "the absolute value of the difference is 5 atomic % or more" is satisfied.

    [0023] For example, when the first laminated structure is constituted by a (Al0.49Ti0.39Cr0.12)N layer and a (Al0.56Ti0.36Cr0.08)N layer, the kinds of the metal elements contained in the two layers are the same. This is because the two layers both contain Al, Ti and Cr. In this case, the difference in the ratios of the numbers of the atoms of Ti contained in the two layers is 3 atomic %. The difference in the ratios of the numbers of the atoms of Cr contained in the two layers is 4 atomic %. These values are each less than 5 atomic %. However, even in this case, the difference in the ratios of the numbers of the atoms of Al contained in the two layers is 7 atomic %, so that the above-mentioned condition that "an absolute value of the difference is 5 atomic % or more" is satisfied.

    [0024] In the present specification, when the nitride is shown as (MaLb)N, it means that an atomic ratio of the M element based on the whole metal elements is a, and an atomic ratio of the L element based on the whole metal elements is b. For example, (Al0.55Ti0.45)N means that an atomic ratio of the Al element based on the whole metal elements is 0.55, and an atomic ratio of the Ti element based on the whole metal elements is 0.45. That is, (Al0.55Ti0.45)N shows that an amount of the Al element based on the whole metal element is 55 atomic %, and an amount of the Ti element based on the whole metal element is 45 atomic %.

    [0025] The metal element(s) contained in the layers constituting the second laminated structure is/are preferably the same as the metal element(s) contained in the other layers constituting the second laminated structure. That is, a plurality of the layers constituting the second laminated structure are preferably constituted by the same kinds of the metal elements. In addition, it is preferred that an absolute value of the difference between a ratio of the specific metal elements contained in a layer constituting the second laminated structure and a ratio of the specific metal elements contained in the other layer constituting the second laminated structure adjacent to the above layer is 5 atomic % or more. "A ratio of the specific metal elements" herein mentioned means a ratio (atomic %) of the number of the atoms of the specific metal elements contained in the layer based on the number of atoms of the whole metal elements contained in the layer.

    [0026] If the second laminated structure employs such a constitution, crystal lattice becomes inconsistent at the boundary surface between the layers without lowering adhesiveness between a layer constituting the second laminated structure and a layer adjacent to the layer. Therefore, cracks are likely propagated to the direction parallel to the boundary surface of the layers constituting the second laminated structure, whereby propagation of the cracks to the substrate can be effectively suppressed. The meaning of the above-mentioned "absolute value of the difference between a ratio of the specific metal elements contained in a layer and a ratio of the specific metal elements contained in the other layers adjacent to the above layer is 5 atomic % or more" is the same as those explained in the above first laminated structure.

    [0027] As the other embodiments of the coated tool of the present invention, it is preferred that one or more kinds of the metal elements contained in a layer constituting the first laminated structure is different from the metal elements contained in the other layer constituting the first laminated structure adjacent to the above layer. If one or more kinds of the metal elements is/are different, crystal lattice becomes inconsistent at the boundary surface between the layers, and cracks are likely propagated to the direction parallel to the boundary surface of the layers, whereby propagation of the cracks to the substrate can be effectively suppressed.

    [0028] For example, when the first laminated structure is constituted by an (Al0.50Ti0.50)N layer and an (Al0.50Ti0.30Cr0.20)N layer, and the metal elements contained in the two layers are compared to each other, the above condition is satisfied. This is because the two layers contains Al and Ti, but Cr is contained in one layer alone.

    [0029] For example, when the first laminated structure is constituted by an (Al0.50Cr0.50)N layer and an (Al0.67Ti0.33)N layer, and the metal elements contained in the two layers are compared to each other, the above condition is satisfied. This is because the two layers contains Al, but Cr and Ti are respectively contained in one layer alone.

    [0030] Similarly, in the coated tool of the present invention, it is preferred that one or more kinds of the metal elements contained in a layer constituting the second laminated structure is different from the metal elements contained in the other layers constituting the second laminated structure adjacent to the above layer. If one or more kinds of the metal elements is/are different, crystal lattice becomes inconsistent at the boundary surface between the layers, and cracks are likely propagated to the direction parallel to the boundary surface of the layers, whereby propagation of the cracks to the substrate can be effectively suppressed.

    [0031] The coated tool of the present invention contains a coating layer. The coating layer contains a first laminated structure. The first laminated structure contains two or more layers comprising the above-mentioned compound. The average thickness of the respective layers contained in the first laminated structure is 60 nm or more and 500 nm or less. Two or more layers contained in the first laminated structure are periodically laminated. The periodically laminated structure contains at least two kinds of layers having different compositions. These two kinds of layers are preferably laminated alternately twice or more. When two kinds of layers having different compositions are laminated alternately twice or more, propagation of the cracks is suppressed, so that fracture resistance of the coated tool is further improved.

    [0032] In the present invention, the minimum unit of the thickness in which lamination of the layers is repeated is called as "laminating cycle".

    [0033] Fig. 1 is an example of a schematic drawing of a cross-sectional structure of the coated tool of the present invention. In the following, the laminating cycle is explained by referring to Fig. 1.

    [0034] For example, Layer A1, Layer B1, Layer C1 and Layer D1 which have different compositions are repeatedly laminated from the substrate (1) toward the surface of the coating layer (2). More specifically, these layers are laminated in the order of Layer A1→Layer B1→Layer C1→Layer D1→Layer A1→Layer B1→Layer C1→Layer D1→···. In this case, the total thickness from Layer A1 to Layer D1 is a "laminating cycle".

    [0035] For example, Layer A1 and Layer B1 which have different compositions are repeatedly laminated from the substrate (1) toward the surface of the coating layer (2). More specifically, these layers are laminated in the order of Layer A1→Layer B1→Layer A1→Layer B1→Layer A1→Layer B→···. In this case, the total of the thickness of Layer A1 and the thickness of Layer B1 is a "laminating cycle".

    [0036] To form the first laminated structure, at least two kinds of layers having different compositions are periodically laminated. The average thickness of the respective layers is 60 nm or more and 500 nm or less. By being formed the first laminated structure as mentioned above, the following effects can be obtained.

    [0037] Cracks generated at the surface of the coating layer during the use of the coated tool reach to the first laminated structure. The cracks reached to the first laminated structure propagate to the direction parallel to the boundary surface of the layers having different compositions. This brings an effect that the propagation of the cracks to the substrate can be prevented. Such an effect can be more heightened by alternately laminating two layers having different compositions twice or more. More specifically, it is preferred that Layer A1 and Layer B1 having different compositions are alternately laminated twice or more from the substrate toward the surface of the coating layer. That is, the first laminated structure preferably contains an alternately laminated structure of Layer A1→Layer B1→Layer A1→Layer B1→···.

    [0038] If the average thickness of the respective layers contained in the first laminated structure is less than 60 nm, propagation of the cracks to the substrate cannot sufficiently be prevented. On the other hand, if the average thickness of the respective layers exceeds 500 nm, fracture resistance of the coated tool is lowered. Therefore, the average thickness of the respective layers contained in the first laminated structure is 60 nm or more and 500 nm or less. The average thickness of the respective layers contained in the first laminated structure is preferably 60 nm or more and 250 nm or less.

    [0039] If the average thickness of the first laminated structure is less than 0.2 µm, a number (a number of repeated times) of periodically laminating the layers having different compositions becomes small. In this case, the effect of suppressing propagation of cracks to the substrate is lowered. On the other hand, if the average thickness of the first laminated structure exceeds 6 µm, residual compressive stress of the whole coating layer becomes high. As a result, peeling or fracture of the coating layer likely occurs, whereby fracture resistance of the coated tool is lowered. Accordingly, the average thickness of the first laminated structure is preferably 0.2 to 6 µm.

    [0040] The coated tool of the present invention contains a coating layer. The coating layer contains a second laminated structure. The second laminated structure contains two or more layers comprising the above-mentioned compound. The average thickness of the respective layers contained in the second laminated structure is 2 nm or more and less than 60 nm. Two or more layers contained in the second laminated structure are periodically laminated. The periodically laminated structure contains at least two kinds of layers having different compositions. These two kinds of layers are preferably laminated alternately twice or more. When two kinds of layers having different compositions are laminated alternately twice or more, hardness of the second laminated structure is high, so that wear resistance of the coated tool is further improved.

    [0041] In the second laminated structure, the minimum unit of the thickness in which lamination of the layers is repeated is called as "laminating cycle".

    [0042] For example, in Fig. 1, Layer A2, Layer B2, Layer C2 and Layer D2 which have different compositions are repeatedly laminated from the substrate (1) toward the surface of the coating layer (2). More specifically, these layers are laminated in the order of Layer A2→Layer B2→Layer C2→Layer D2→Layer A2→Layer B2→Layer C2→Layer D2→···. In this case, the total thickness from Layer A2 to Layer D2 is a "laminating cycle".

    [0043] For example, Layer A2 and Layer B2 which have different compositions are repeatedly laminated from the substrate (1) toward the surface of the coating layer (2). More specifically, these layers are laminated in the order of Layer A2→Layer B2→Layer A2→Layer B2→Layer A2→Layer B2→···. In this case, total of the thickness of Layer A2 and the thickness of Layer B2 is a "laminating cycle".

    [0044] To form the second laminated structure, at least two kinds of layers having different compositions are periodically laminated. The average thickness of the respective layers is 2 nm or more and less than 60 nm. By the second laminated structure being thus formed, hardness of the second laminated structure becomes high whereby wear resistance of the coated tool improves. Such an effect can be more heightened by alternately laminating two layers having different compositions twice or more. More specifically, it is preferred that Layer A2 and Layer B2 having different compositions are alternately laminated twice or more from the substrate toward the surface of the coating layer. That is, the second laminated structure preferably contains an alternately laminated structure of Layer A2→Layer B2→Layer A2→Layer B2→···.

    [0045] If the average thickness of the respective layers contained in the second laminated structure is less than 2 nm, it is difficult to form a layer having a uniform thickness. If the average thickness of the respective layers contained in the second laminated structure is 60 nm or more, hardness of the second laminated structure is lowered, so that wear resistance of the coated tool is lowered. Further, in this case, difference between the thickness of the second laminated structure and the thickness of the first laminated structure becomes small. As a result, cracks to the direction parallel to the boundary surface of the first laminated structure and the second laminated structure do not propagate, whereby propagation of the cracks to the substrate cannot sufficiently be suppressed. Therefore, the average thickness of the respective layers contained in the second laminated structure is 2 nm or more and less than 60 nm. The average thickness of the respective layers contained in the second laminated structure is preferably 5 nm or more and 30 nm or less.

    [0046] If the average thickness of the second laminated structure is less than 0.02 µm, a number (a number of repeated times) of periodically laminating the layers having different compositions becomes small. In this case, the effect of improving hardness of the second laminated structure cannot be obtained. On the other hand, if the average thickness of the second laminated structure exceeds 6 µm, residual compressive stress of the second laminated structure becomes high. As a result, peeling or fracture of the coating layer likely occurs, whereby fracture resistance of the coated tool is lowered. Accordingly, the average thickness of the second laminated structure is preferably 0.02 to 6 µm.

    [0047] The coated tool of the present invention contains a coating layer. The coating layer contains the first laminated structure excellent in fracture resistance and the second laminated structure excellent in wear resistance. Accordingly, the coated tool of the present invention is excellent in fracture resistance and wear resistance. The coating layer may contain an upper layer. The upper layer is a layer positioned at the surface side of the coating layer than the first laminated structure and the second laminated structure. The surface side of the coating layer means a side of the coating layer positioned opposite to the substrate. In addition, the coating layer may contain a lower layer. The lower layer is a layer positioned at the substrate side than the first laminated structure and the second laminated structure.

    [0048] Constitutions of the upper layer and the lower layer are not particularly limited. The upper layer and the lower layer preferably contain at least one metal element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Sr, Y, Sn and Bi. Further, the upper layer and the lower layer preferably contain a compound comprising at least one kind of a metal element selected from these metal elements and at least one non-metal element selected from the group consisting of carbon, nitrogen, oxygen and boron. Constitutions of the upper layer and the lower layer are preferably a monolayer or a non-periodical multi-layer. When the upper layer and the lower layer have such a constitution, wear resistance of the upper layer and the lower layer is improved.

    [0049] The first laminated structure and the second laminated structure are preferably laminated two or more alternately and continuously. If the first laminated structure and the second laminated structure are alternately laminated, cracks are likely propagated to the direction parallel to the boundary surface of the first laminated structure and the second laminated structure. As a result, propagation of the cracks to the substrate can be suppressed, whereby fracture resistance of the coated tool is improved.

    [0050] Positional relationship of the first laminated structure and the second laminated structure is not particularly limited. The positional relationship of the first laminated structure and the second laminated structure are, for example, any of the following (1) to (4).
    1. (1) The first laminated structure is nearest to the substrate, and the second laminated structure is nearest to the surface of the coating layer.
    2. (2) The second laminated structure is nearest to the substrate, and the first laminated structure is nearest to the surface of the coating layer.
    3. (3) The first laminated structure is nearest to the substrate, and is nearest to the surface of the coating layer.
    4. (4) The second laminated structure is nearest to the substrate, and is nearest to the surface of the coating layer.


    [0051] In the above-mentioned (1) to (4), "the surface of the coating layer" means a surface of the coating layer positioned opposite to the substrate.

    [0052] Among the above-mentioned positional relationship, (1) is preferred. When the positional relationship of the first laminated structure and the second laminated structure is the above-mentioned (1), residual compressive stress of the first laminated structure is lower than residual compressive stress of the second laminated structure, so that peeling resistance of the coating layer tends to be improved.

    [0053] The average thickness of the first laminated structure and/or the second laminated structure is continuously or stepwisely reduced from the substrate side toward the surface side of the coating layer. This is because fracture resistance can be improved without lowering wear resistance of the coating layer.

    [0054] At the surface side of the coating layer, the average thickness(es) of the first laminated structure and/or the second laminated structure is/are decreased, so that a distance between boundary surfaces of the first laminated structures and the second laminated structures becomes short. When the distance between boundary surfaces of the first laminated structure and the second laminated structure becomes short, cracks are likely propagated to the direction parallel to the boundary surface of the first laminated structure and the second laminated structure. As a result, an effect of suppressing propagation of the cracks to the substrate can be obtained as well as fracture resistance is improved. Therefore, if the average thickness of either of the first laminated structure or the second laminated structure is made thin, fracture resistance is improved. If both of the average thicknesses of the first laminated structure and the second laminated structure are made thin, fracture resistance is further improved.

    [0055] In the present invention, "continuously reduced" means, for example, that the thickness(es) of the first laminated structure and/or the second laminated structure is/are reduced from the substrate side toward the surface side with a certain regularity such as a proportional relationship. However, "continuously reduced" is not limited only to the case where the thickness(es) of the first laminated structure and/or the second laminated structure is/are reduced in accordance with the proportional relationship. For example, "continuously reduced" includes the case where the thickness(es) of the first laminated structure and/or the second laminated structure is/are reduced in accordance with the relation of inverse proportion or exponential relationship. In addition, "continuously reduced" also includes the case where the thickness tends to be reduced from the substrate side toward the surface side. This is because, even in this case, the effect of the present invention can be obtained. For example, the case where a part of the thickness of the coating layer is slightly increased from the substrate side toward the surface side is also included in the scope of the right of the present invention.

    [0056] In the present invention, "stepwisely reduced" means, for example, that the thickness(es) of the first laminated structure and/or the second laminated structure is/are reduced irregularly from the substrate side toward the surface side. For example, "stepwisely reduced" includes the case where the thickness of the first laminated structure and/or the second laminated structure at the outermost surface alone is/are reduced. In addition, "stepwisely reduced" also includes the case where the thickness tends to be reduced from the substrate side toward the surface side. This is because, even in this case, the effect of the present invention can be obtained. For example, the case where a part of the thickness of the coating layer is slightly increased from the substrate side toward the surface side is also included in the scope of the right of the present invention.

    [0057] When the average thickness of the first laminated structure nearest to the surface of the coating layer is made TA1, and the average thickness of the first laminated structure nearest to the substrate is made TB1, then a ratio of TA1 to TB1 ((TA1/TB1)×100) is preferably 5% or more and 50% or less, more preferably 5% or more and 30% or less. If the ratio of TA1 to TB1 is less than 5%, the effect of suppressing propagation of the cracks to the substrate may be lowered. On the other hand, if the ratio of TA1 to TB1 exceeds 50%, the effect of suppressing propagation of the cracks to the substrate may be lowered.

    [0058] When the average thickness of the second laminated structure nearest to the surface of the coating layer is made TA2, and the average thickness of the second laminated structure nearest to the substrate is made TB2, then a ratio of TA2 to TB2 ((TA2/TB2)×100) is preferably 5% or more and 50% or less, more preferably 5% or more and 30% or less. If the ratio of TA2 to TB2 is less than 5%, the effect of suppressing propagation of the cracks to the substrate may be lowered. Further, wear resistance is also lowered in some cases. On the other hand, if the ratio of TA2 to TB2 exceeds 50%, the effect of suppressing propagation of the cracks to the substrate may be lowered.

    [0059] The average thickness of the respective layers constituting the first laminated structure and the second laminated structure is preferably reduced continuously or stepwisely from the substrate side toward the surface side of the coating layer. This is because lowering in wear resistance can be suppressed, whereby fracture resistance is improved.

    [0060] In the present invention, "continuously reduced" means, for example, that the average thickness of the respective layers constituting the first laminated structure and/or the second laminated structure are reduced from the substrate side toward the surface side with a certain regularity such as a proportional relationship. However, "continuously reduced" is not limited only to the case where the average thickness of the respective layers constituting the first laminated structure and/or the second laminated structure is reduced in accordance with the proportional relationship. For example, "continuously reduced" includes the case where the thicknesses of the respective layers are reduced in accordance with the relation of inverse proportion or exponential relationship. In addition, "continuously reduced" also includes the case where the thickness tends to be reduced from the substrate side toward the surface side. This is because, even in this case, the effect of the present invention can be obtained. For example, the case where a part of the thickness of the coating layer is slightly increased from the substrate side toward the surface side is also included in the scope of the right of the present invention.

    [0061] In the present invention, "stepwisely reduced" means, for example, that the thicknesses of the respective layers constituting the first laminated structure and/or the second laminated structure are reduced irregularly from the substrate side toward the surface side. For example, "stepwisely reduced" includes the case where the thicknesses of the respective layers constituting the first laminated structure and/or the second laminated structure at the outermost surface alone are reduced. In addition, "stepwisely reduced" also includes the case where the thickness tends to be reduced from the substrate side toward the surface side. This is because, even in this case, the effect of the present invention can be obtained. For example, the case where a part of the thickness of the coating layer is slightly increased from the substrate side toward the surface side is also included in the scope of the right of the present invention.

    [0062] When the average thickness of the layers contained in the first laminated structure nearest to the surface of the coating layer is made TC1, and the average thickness of the layers contained in the first laminated structure nearest to the substrate is made TD1, then a ratio of TC1 to TD1 ((TC1/TD1)×100) is preferably 12% or more and 70% or less, more preferably 30% or more and 60% or less. If the ratio of TC1 to TD1 is less than 12%, hardness of the surface side of the coating layer becomes high, whereby fracture resistance tends to be lowered. On the other hand, if the ratio of TC1 to TD1 exceeds 70%, wear resistance of the surface side of the coating layer tends to be lowered.

    [0063] Incidentally, "the average thickness of the layers contained in the first laminated structure" is a value obtained as follows.

    [0064] For example, when Layer A1 and Layer B1 are laminated in this order repeating 100 times as Layer A1→Layer B1→Layer A1→Layer B1→Layer A1→Layer B1→···, the sum of the laminating cycles repeated 100 times is obtained. Next, a value in which the sum of the laminating cycles is divided by 100 which is a number of the times repeated is obtained. This value is "the average thickness of the layers contained in the first laminated structure". That is, when the first laminated structure comprises "Layer A1→Layer B1→Layer A1→Layer B1→Layer A1→Layer B1→···", the average thickness of "Layer A1→Layer B1" is "the average thickness of the layers contained in the first laminated structure".

    [0065] When the average thickness of the layers contained in the second laminated structure nearest to the surface of the coating layer is made TC2, and the average thickness of the layers contained in the second laminated structure nearest to the substrate is made TD2, then a ratio of TC2 to TD2 ((TC2/TD2)×100) is preferably 5% or more and 70% or less, more preferably 30% or more and 60% or less. If the ratio of TC2 to TD2 is less than 5%, hardness of the surface side of the coating layer becomes high, whereby fracture resistance tends to be lowered. On the other hand, if the ratio of TC2 to TD2 exceeds 70%, wear resistance of the surface side of the coating layer tends to be lowered.

    [0066] Incidentally, "the average thickness of the layers contained in the second laminated structure" is a value obtained as follows.

    [0067] For example, when Layer A2 and Layer B2 are laminated in this order repeating 100 times as Layer A2→Layer B2→Layer A2→Layer B2→Layer A2→Layer B2→···, the sum of the laminating cycles repeated 100 times is obtained. Next, a value in which the sum of the laminating cycles is divided by 100 which is a number of the times repeated is obtained. This value is "the average thickness of the layers contained in the second laminated structure". That is, when the second laminated structure comprises "Layer A2→Layer B2→Layer A2→Layer B2→Layer A2→Layer B2→···", the average thickness of "Layer A2→Layer B2" is "the average thickness of the layers contained in the second laminated structure".

    [0068] A process for preparing the coating layer in the coated tool of the present invention is not particularly limited. For example, the coating layer can be prepared by the physical vapor deposition method such as the ion plating method, the arc ion plating method, the sputtering method and the ion mixing method, etc. For example, the first laminated structure and the second laminated structure explained above can be formed on the substrate by the physical vapor deposition method. In particular, the coating layer formed by the arc ion plating method has high adhesiveness to the substrate. Accordingly, among these methods, the arc ion plating method is preferred.

    [0069] The respective layers can be formed onto the surface of the substrate by the conventional coating method. According to the above, the coated tool of the present invention can be prepared.

    [0070] The process for preparing the coated tool of the present invention is, for example, as follows.

    [0071] A substrate processed to a tool shape is charged in a reaction vessel of a physical vapor deposition device. Next, inside the reaction vessel is evacuated until a pressure becomes 1×10-2 Pa or lower. After evacuation, the substrate is heated to 200 to 800°C by a heater in the reaction vessel. After heating, an Ar gas is introduced into the reaction vessel, and the pressure is made 0.5 to 5.0 Pa. Under the Ar gas atmosphere with the pressure of 0.5 to 5.0 Pa, a bias voltage with -200 to -1000V is applied to the substrate. A current with 5 to 20A is passed through the tungsten filament in the reaction vessel. The surface of substrate is subjected to an ion bombardment treatment by an Ar gas. After the surface of the substrate is subjected to the ion bombardment treatment, the reaction vessel is evacuated so that a pressure inside thereof becomes 1×10-2 Pa or lower.

    [0072] Then, a reaction gas such as a nitrogen gas, etc., is introduced into the reaction vessel. By making the pressure in the reaction vessel 0.5 to 5.0 Pa, a bias voltage with -10 to -150V is applied to the substrate. By evaporating the metal evaporation sources depending on the metal components of the respective layers by an arc discharge, the respective layers can be formed onto the surface of the substrate. Incidentally, two or more kinds of metal evaporation sources placed in a position apart from each other are evaporated by an arc discharge, and the table onto which a substrate has been fixed is rotated to form a layer constituting the first laminated structure or the second laminated structure. In this case, by adjusting a rotation number of the table onto which the substrate has been fixed in the reaction vessel, the thicknesses of the respective layers constituting the first laminated structure or the second laminated structure can be controlled. By alternately evaporating two or more kinds of metal evaporation sources by an arc discharge, a layer constituting the first laminated structure or the second laminated structure can be also formed. In this case, by adjusting arc discharge times of the metal evaporation sources respectively, the thicknesses of the respective layers constituting the first laminated structure or the second laminated structure can be controlled.

    [0073] The thicknesses of the respective layers constituting the coating layer and the thicknesses of the respective laminated structures can be measured by observing the cross-sectional structure of the coated tool. For example, the thicknesses of the respective layers constituting the coating layer and the thicknesses of the respective laminated structures can be measured by using optical microscope, scanning electron microscope (SEM), transmission electron microscope (TEM), etc.

    [0074] The average thicknesses of the respective layers constituting the coating layer and the average thicknesses of the respective laminated structures can be obtained as follows.

    [0075] At the position nearer to 50 µm from the cutting edge of the surface opposed to the metal evaporation sources toward the center portion of said surface, the cross-sectional surface of the coated tool is observed at the three portions or more. From the observed cross-sectional surface, thicknesses of the respective layers and thicknesses of the respective laminated structure are measured. By calculating the average value of the measured thicknesses, the average thickness can be obtained.

    [0076] The compositions of the respective layers of the coated tool of the present invention can be measured from the cross-sectional structure of the coated tool by using an energy dispersive X-ray spectrometry (EDS) or a wavelength dispersive X-ray spectrometry (WDS), etc.

    [0077] A kind of the coated tool of the present invention may be specifically a tool for milling or turning. Examples of such a tool may be an indexable cutting insert, a drill and an end mill.

    [0078] Among the following "Present Products" 1 to 30 in Tables 1 to 23, Present Products 21, 22 and 24 are examples of the present invention as defined by claim 1. Other products are presented for illustrative purpose.

    [Example 1]



    [0079] A cemented carbide corresponding to P10 with an ISO standard SEEN1203AGTN insert shape was prepared as the substrate. In the reaction vessel of an arc ion plating device, metal evaporation sources which became the compositions of the respective layers shown in Table 1 and Table 2 were arranged. The prepared substrate was fixed to fixing metal fitting of a rotary table in the reaction vessel.

    [0080] Thereafter, inside the reaction vessel was evacuated until the pressure therein became 5.0×10-3 Pa or lower. After evacuation, the substrate was heated by a heater in the reaction vessel until the temperature thereof became 500°C. After heating, an Ar gas was introduced into the reaction vessel so that the pressure in the reaction vessel became 5.0 Pa.

    [0081] At an Ar gas atmosphere with a pressure of 5.0 Pa, a bias voltage with - 1,000V was applied to the substrate. A current of 10A was passed through the tungsten filament in the reaction vessel. Under such conditions, the ion bombardment treatment by an Ar gas was carried out for 30 minutes to the surface of the substrate. After completion of the ion bombardment treatment, inside the reaction vessel was evacuated until the pressure in the reaction vessel became 5.0×10-3 Pa or lower.

    [0082] After evacuation, a nitrogen gas was introduced into the reaction vessel, and inside the reaction vessel was made a nitrogen gas atmosphere with a pressure of 2.7 Pa. A bias voltage of -50V was applied to the substrate. The respective layers were formed by evaporating the metal evaporation sources by an arc discharge with an arc current of 200A.

    [0083] When Layer A1 and Layer B1 of Present products 1 to 9 and Comparative products 1 and 2 were to be formed, the metal evaporation sources of Layer A1 and the metal evaporation sources of Layer B1 were alternately evaporated by an arc discharge to form Layer A1 and Layer B1. At this time, the respective arc discharge times were so adjusted that Layer A1 and Layer B1 have the thicknesses shown in Table 3. In Comparative product 3 having a thick thickness of the layer, the metal evaporation sources of Layer X and the metal evaporation sources of Layer Y were similarly evaporated by the arc discharge alternately to form Layer X and Layer Y. At this time, the thickness of Layer X and the thickness of Layer Y were controlled by adjusting the arc discharge time at the time of forming the respective layers.

    [0084] When Layer A2 and Layer B2 of Present products 1 to 9 and Comparative products 1 and 2 were to be formed, the metal evaporation sources of Layer A2 and the metal evaporation sources of Layer B2 were evaporated by an arc discharge simultaneously to form Layer A2 and Layer B2. At this time, the number of rotation of the table was adjusted within the range of 0.2 to 10 min-1 so that Layer A2 and Layer B2 have the thicknesses shown in Table 3. In Comparative product 4 having a thin thickness of the layer, the metal evaporation sources of Layer X and the metal evaporation sources of Layer Y were similarly evaporated by the arc discharge simultaneously to form Layer X and Layer Y. At this time, the thickness of Layer X and the thickness of Layer Y were controlled by adjusting the number of rotation of the table within the range of 0.2 to 10 min-1.

    [0085] Comparative product 5 is constituted by layers having a thin thickness and layers having a thick thickness alternately laminated. The thicknesses of the layers constituting Comparative product 5 were controlled by adjusting the arc discharge time and the number of rotation of the table. The number of rotation of the table was adjusted within the range of 0.2 to 10 min-1.

    [0086] The monolayer of Comparative product 6 was formed by evaporating the metal evaporation sources by an arc discharge with an arc current of 200A while applying a bias voltage of -50V to the substrate.

    [0087] The respective layers were formed onto the surface of the substrate until the layers became predetermined thicknesses shown in Table 3 and Table 4. Thereafter, a power of the heater was turned off, and after the temperature of the sample became 100°C or lower, the sample was taken out from the reaction vessel.
    [Table 1]
    Sample No.First laminated structureSecond laminated structure
    LAYER A1LAYER B1LAYER A2LAYER B2
    CompositionCompositionCompositionComposition
    Present 1 (Ti0.50Al0.50)N (Ti0.67Al0.33)N (Ti0.50Al0.50)N (Ti0.67Al0.33)N
    Present product 2 (Ti0.50Al0.50)N (Ti0.67Al0.33)N (Ti0.50Al0.50)N (Ti0.67Al0.33)N
    Present product 3 (Ti0.50Al0.50)N (Ti0.67Al0.33)N (Ti0.50Al0.50)N (Ti0.67Al0.33)N
    Present product 4 (Ti0.50Al0.50)N (Ti0.67Al0.33)N (Ti0.50Al0.50)N (Ti0.67Al0.33)N
    Present product 5 (Ti0.50Al0.50)N (Ti0.33Al0.67)N (Ti0.50Al0.50)N (Ti0.33Al0.67)N
    Present product 6 (Ti0.50Al0.50)N (Ti0.33Al0.67)N (Ti0.50Al0.50)N (Ti0.33Al0.67)N
    Present product 7 (Ti0.67Al0.33)N (Ti0.33Al0.67)N (Ti0.67Al0.33)N (Ti0.33Al0.67)N
    Present product 8 (Ti0.67Al0.33)N (Ti0.33Al0.67)N (Ti0.67Al0.33)N (Ti0.33Al0.67)N
    Present product 9 (Ti0.50Al0.50)N (Ti0.67Al0.33)N (Ti0.50Al0.50)N (Ti0.67Al0.33)N
    Comparative product 1 (Ti0.50Al0.50)N (Ti0.67Al0.33)N (Ti0.50Al0.50)N (Ti0.67Al0.33)N
    Comparative product 2 (Ti0.67Al0.33)N (Ti0.33Al0.67)N (Ti0.67Al0.33)N (Ti0.33Al0.67)N
    [Table 2]
    Sample No.Coating layer
    Alternate laminateTotal thickness (µm)
    CompositionAverage thickness
    LAYER XLAYER YLAYER XLAYER YLAYER X and LAYER Y
    (nm)(nm)Repeated times (times)
    Comparative product 3 (Ti0.50Al0.50)N (Ti0.67Al0.33)N 100 100 20 4.00
    Comparative product 4 (Ti0.67Al0.33)N (Ti0.50Al0.50)N 10 10 200 4.00
    Comparative product 5 (Ti0.67Al0.33)N (Ti0.33Al0.67)N 10 100 40 4.40
    Comparative product 6 Ti0.50Al0.50)N Monolayer 4.00
    [Table 3]
    Sample No.First laminated structureSecond laminated structure
    LAYER A1LAYER B1LAYER A2LAYER B2
    Average thickness (nm)Average thickness (nm)Average thickness (nm)Average thickness (nm)
    Present product 1 100 100 10 10
    Present product 2 60 60 2 2
    Present product 3 250 250 10 10
    Present product 4 100 100 55 55
    Present product 5 300 300 50 50
    Present product 6 200 200 2 2
    Present product 7 100 100 10 10
    Present product 8 80 80 2 2
    Present product 9 150 150 30 30
    Comparative product 1 100 100 10 10
    Comparative product 2 200 200 2 2
    [Table 4]
    Sample No.Coating layer
    First layer (Substrate side)Second layerThird layerFourth layerFifth layerSixth layer (Surface side)Total thickness (µm)
    Layer A1 and Layer B1Layer A2 and Layer B2Layer A1 and Layer B1Layer A2 and Layer B2Layer A1 and Layer B1Layer A2 and Layer B2
    Laminated structureRepeated times (times)Average thickness (µm) TB1Laminated structureRepeated times (times)Average thickness (µm) TB2Laminated structureRepeated times (times)Average thickness (µm)Laminated structureRepeated times (times)Average thickness (µm)Laminated structureRepeated times (times)Average thickness (µm) TA1Laminated structureRepeated times (times)Average thickness (µm) TA2
    Present product 1 First 6 1.20 Second 50 1.00 First 4 0.80 Second 30 0.60 First 2 0.40 Second 10 0.20 4.20
    Present product 2 First 8 0.96 Second 250 1.00 First 6 0.72 Second 150 0.60 First 4 0.48 Second 50 0.20 3.96
    Present product 3 First 4 2.00 Second 50 1.00 First 2 1.00 Second 20 0.40 - - - - - - 4.40
    Present product 4 First 6 1.20 Second 20 2.20 First 4 0.80 Second 10 1.10 First 2 0.40 Second 5 0.55 6.25
    Present product 5 First 8 4.80 Second 30 3.00 First 4 2.40 Second 15 1.50 - - - - - - 11.70
    Present product 6 First 15 6.00 Second 120 0.48 First 4 1.60 Second 28 0.11 First 2 0.80 Second 10 0.04 9.03
    Present product 7 First 6 1.20 Second 300 6.00 First 2 0.40 Second 70 1.40 - - - - - - 9.00
    Present product 8 First 8 1.28 Second 8 0.03 First 2 0.32 Second 4 0.02 - - - - - - 1.65
    Present product 9 First 10 3.00 Second 10 0.60 First 3 0.90 Second 10 0.60 First 2 0.60 Second 10 0.60 6.30
    Comparative product 1 First 5 1.00 Second 50 1.00 First 5 1.00 Second 50 1.00 First 5 1.00 Second 50 1.00 6.00
    Comparative product 2 First 3 1.20 Second 50 0.20 First 3 1.20 Second 50 0.20 First 3 1.20 Second 50 0.20 4.20
    *"First" and "Second" at the column of "Laminated structure" mean the first laminated structure and the second laminated structure of the Present product with the corresponding number in Table 1 and Table 2.
    [Table 5]
    Sample No.First laminated structureSecond laminated structure
    Average thickness Surface side/Substrate side (%)Reduction in average thicknessAverage thickness Surface side/Substrate side (%)Reduction in average thickness
    (TA1/TB1)×100(TA2/TB2)×100
    Present product 1 33 Continuous 20 Continuous
    Present product 2 50 Continuous 20 Continuous
    Present product 3 50 Stepwise 40 Stepwise
    Present product 4 33 Continuous 25 Continuous
    Present product 5 50 Continuous 50 Continuous
    Present product 6 13 Stepwise 8 Stepwise
    Present product 7 33 Stepwise 23 Stepwise
    Present product 8 25 Stepwise 50 Stepwise
    Present product 9 20 Stepwise 100 Not reduced
    Comparative product 1 100 Not reduced 100 Not reduced
    Comparative product 2 100 Not reduced 100 Not reduced


    [0088] The average thicknesses of the respective layers and the average thickness of the respective laminated structures of the obtained samples were obtained as follows.

    [0089] Cross-sectional surfaces at the three portions were observed by TEM at the neighbor of the position of 50 µm from the cutting edge at the surface opposed to the metal evaporation sources of the coated tool toward the center portion of said surface. The thicknesses of the respective layers and the thicknesses of the respective laminated structures were measured, and an average value of the measured thicknesses was calculated.

    [0090] The compositions of the respective layers of the obtained samples were obtained as follows.

    [0091] The compositions were measured by using EDS at the cross-sectional surface at the position of 50 µm from the cutting edge at the surface opposed to the metal evaporation sources of the coated tool toward the center portion of said surface.

    [0092] These measured results are also shown in Tables 1 to 4.

    [0093] Incidentally, compositional ratios of metal elements of the respective layers in Tables 1 to 4 show an atomic ratio of the respective metal elements based on the whole metal elements in the metal compounds constituting the respective layers.

    [0094] From the average thickness of the first laminated structure shown in Table 4, a ratio of the average thickness of the first laminated structure nearest to the surface of the coating layer based on the average thickness of the first laminated structure nearest to the substrate was obtained. Similarly, from the average thickness of the second laminated structure shown in Table 4, a ratio of the average thickness of the second laminated structure nearest to the substrate based on the average thickness of the second laminated structure nearest to the surface of the coating layer was obtained. These results are shown in Table 5.

    [0095] By using the obtained samples, the following Cutting test 1 and Cutting test 2 were carried out, and fracture resistance and wear resistance were evaluated. The evaluation results are shown in Table 6.

    [Cutting test 1: Evaluation of fracture resistance]
    Work piece material: SCM440,
    Shape of work piece material: a rectangular parallelepiped with 105 mm×220 mm×60 mm (provided that six holes with a diameter of ϕ 40 mm have been drilled at the surface with 105 mm×220 mm of the rectangular parallelepiped at which face milling processing is to be carried out.)
    Cutting speed: 260 m/min,
    Feed: 0.4 mm/tooth,
    Depth of cut: 2.0 mm,
    Cutting width: 105 mm,
    Coolant: none,
    Cutter effective diameter: ϕ 125 mm,
    Evaluation item: A processed length until the sample had been defected (defect is generated at the cutting blade portion of the sample) was measured as the tool life. A processed length until the sample had fractured was measured.

    [Cutting test 2: Evaluation of wear resistance]
    Work piece material: SCM440,
    Shape of work piece material: a rectangular parallelepiped with 105 mm×220 mm×60 mm,
    Cutting speed: 260 m/min,
    Feed: 0.12 mm/tooth,
    Depth of cut: 2.0 mm,
    Cutting width: 50 mm,
    Coolant: none,
    Cutter effective diameter: ϕ 100 mm,
    Evaluation item: A processed length until the maximum flank wear width had become 0.2 mm was the tool life. The processed length until the maximum flank wear width had reached 0.2 mm was measured.



    [0096] Evaluation standard of the processed length until the tool reaches its tool life in Cutting test 1 is as follows.
    ⊚: 11 m or more
    ○: 10.5 m or more and less than 11 m
    △: 10 m or more and less than 10.5 m
    ×: Less than 10 m

    [0097] Evaluation standard of the processed length until the tool reaches its tool life in Cutting test 2 is as follows.
    ⊚: 5 m or more
    ○: 4.5 m or more and less than 5 m
    △: 4 m or more and less than 4.5 m
    ×: Less than 4 m

    [0098] An order of the evaluation is (Excellent) ⊚>○>△>× (Poor). The evaluation of ⊚ or ○ means that cutting performance is excellent. The results of the obtained total evaluation are shown in Table 6.
    [Table 6]
    Sample No.Cutting test 1 Wear resistance testCutting test 2 Fracture resistance test
    Tool life (m)EvaluationTool life (m)Evaluation
    Present product 1 10.2 Δ 5.4
    Present product 2 10.5 5.1
    Present product 3 10.3 Δ 5.3
    Present product 4 10.5 5.9
    Present product 5 11.5 5.7
    Present product 6 12.1 5.5
    Present product 7 10.8 6.7
    Present product 8 12.7 4.7
    Present product 9 10.7 5.1
    Comparative product 1 10.3 Δ 4.2 Δ
    Comparative product 2 10.4 Δ 3.8 ×
    Comparative product 3 9.7 × 3.8 ×
    Comparative product 4 9.6 × 3.6 ×
    Comparative product 5 9.7 × 3.7 ×
    Comparative product 6 8.5 × 3.3 ×


    [0099] From the results of Table 6, the results of the wear resistance test of Present products were △ or higher. The results of the wear resistance of Present products were equal to those of Comparative products or more in the point of not evaluated to as ×. In addition, the results of the fracture resistance test of all the Present products were ⊚ or ○. The results of the fracture resistance test of Comparative products were △ or ×. From these results, it can be understood that Present products are excellent in fracture resistance than Comparative products. From these results, it can be understood that tool lives of Present products are elongated. As can be seen from these results, according to the present disclosure, fracture resistance could be improved without lowering wear resistance of the coated tool.

    [Example 2]



    [0100] A cemented carbide corresponding to P10 with an ISO standard SEEN1203AGTN insert shape was prepared as the substrate. In the reaction vessel of an arc ion plating device, metal evaporation sources which became the compositions of the respective layers shown in Table 7 were arranged. According to the same preparation method as in Example 1, the samples having layer constitutions shown in Tables 8 and 9 were prepared.

    [0101] Present product 10 and Comparative product 10 were prepared as follows.

    [0102] In the reaction vessel of the arc ion plating device, metal evaporation sources which became the compositions of the respective layers shown in Table 7 were arranged. A mixed gas of an N2 gas and a CH4 gas was introduced into the reaction vessel. A partial pressure ratio of the N2 gas and the CH4 gas in the mixed gas is N2:CH4=1:1. A pressure in the reaction vessel is 2.7 Pa. The respective layers were prepared in the same manner as in Example 1 except for setting the atmosphere in the reaction vessel as mentioned above, and the samples having layer constitutions shown in Tables 8 and 9 were prepared.

    [0103] Present product 18 was prepared as follows.

    [0104] In the reaction vessel of the arc ion plating device, metal evaporation sources which became the compositions of the respective layers shown in Table 7 were arranged. When an oxide layer was to be formed, an O2 gas was introduced into the reaction vessel, and a pressure in the reaction vessel was controlled to 2.7 Pa. Thereafter, when a nitride layer was to be formed, the O2 gas was exhausted from the reaction vessel, an N2 gas was introduced into the reaction vessel, and a pressure in the reaction vessel was controlled to 2.7 Pa. The samples having layer constitutions shown in Tables 8 and 9 were prepared in the same manner as in Example 1 except for setting the atmosphere in the reaction vessel as mentioned above.
    [Table 7]
    Sample No.First laminated structureSecond laminated structure
    LAYER A1LAYER B1LAYER A2LAYER B2
    CompositionCompositionCompositionComposition
    Present product 10 (Ti0.50Al0.50)CN (Ti0.67Al0.33)CN (Ti0.50Al0.50)CN (Ti0.67Al0.33)CN
    Present product 11 (Ti0.50Al0.50)N (Al0.45Ti0.45Si0.10)N (Ti0.50Al0.50)N (Al0.45Ti0.45Si0.10)N
    Present product 12 (Ti0.50Al0.50)N (Al0.45Ti0.45Sr0.10)N (Ti0.50Al0.50)N (Al0.45Ti0.45Sr0.10)N
    Present product 13 (Ti0.50Al0.50)N (Al0.45Ti0.45Y0.10)N (Ti0.50Al0.50)N (Al0.45Ti0.45Y0.10)N
    Present product 14 (Ti0.50Al0.50)N (Al0.50Ti0.30Cr0.20)N (Ti0.50Al0.50)N (Al0.50Ti0.30Cr0.20)N
    Present product 15 (Ti0.50Al0.50)N (Al0.50Ti0.45Nb0.05)N (Ti0.50Al0.50)N (Al0.50Ti0.45Nb0.05)N
    Present product 16 (Ti0.67Al0.33)N (Al0.50Ti0.45Ta0.05)N (Ti0.67Al0.33)N (Al0.50Ti0.45Ta0.05)N
    Present product 17 (Ti0.67Al0.33)N (Al0.50Ti0.45W0.05)N (Ti0.67Al0.33)N (Al0.50Ti0.45W0.05)N
    Present product 18 (Al0.50Cr0.50)2O3 (Ti0.90Si0.10)N (Al0.50Cr0.50)2O3 (Ti0.90Si0.10)N
    Present product 19 (Ti0.50Al0.50)N (Al0.50Cr0.50)N (Ti0.50Al0.50)N (Al0.50Cr0.50)N
    Present product 20 TiN (Ti0.40Al0.30Cr0.20Si0.10)N TiN (Ti0.40Al0.30Cr0.20Si0.10)N
    Comparative product 7 (Ti0.50Al0.50)N (Al0.50Ti0.30Cr0.20)N (Ti0.50Al0.50)N (Al0.50Ti0.30Cr0.20)N
    Comparative product 8 TiN (Ti0.40Al0.30Cr0.20Si0.10)N TiN (Ti0.40Al0.30Cr0.20Si0.10)N
    Comparative product 9 (Ti0.67Al0.33)N (Ti0.90Si0.10)N (Ti0.67Al0.33)N (Ti0.90Si0.10)N
    Comparative product 10 (Ti0.50Al0.50)CN (Ti0.67Al0.33)CN (Ti0.50Al0.50)CN (Ti0.67Al0.33)CN
    [Table 8]
    Sample No.First laminated structureSecond laminated structure
    LAYER A1LAYER B1LAYER A2LAYER B2
    Average thickness (nm)Average thickness (nm)Average thickness (nm)Average thickness (nm)
    Present product 10 100 100 10 10
    Present product 11 100 100 10 10
    Present product 12 100 100 10 10
    Present product 13 100 100 10 10
    Present product 14 100 100 10 10
    Present product 15 100 100 10 10
    Present product 16 100 100 10 10
    Present product 17 100 100 10 10
    Present product 18 100 100 10 10
    Present product 19 100 100 10 10
    Present product 20 100 100 10 10
    Comparative product 7 100 100 10 10
    Comparative product 8 100 100 10 10
    Comparative product 9 100 100 10 10
    Comparative product 10 100 100 10 10
    [Table 9]
    Sample No.Coating layer
    First layer (Substrate side)Second layerThird layerFourth layerFifth layerSixth layer (Surface side)Total thickness (µm)
    Layer A1 and Layer B 1Layer A2 and Layer B2Layer A1 and Layer B 1Layer A2 and Layer B2Layer A1 and Layer B1Layer A2 and Layer B2
    Laminated structureRepeated times (times)Average thickness (µM) TB1Laminated structureRepeated times (times)Average thickness (µm) TB2Laminated structureRepeated times (times)Average thickness (µm)Laminated structureRepeated times (times)Average thickness (µm)Laminated structureRepeated times (times)Average thickness (µm) TA1Laminated structureRepeated times (times)Average thickness (µm) TA2
    Present product 10 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 11 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 12 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 13 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 14 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 15 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 16 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 17 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 18 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Present product 19 First 4 0.80 Second 70 1.40 First 4 0.80 Second 40 0.80 First 4 0.80 Second 10 0.20 4.80
    Present product 20 First 6 1.20 Second 70 1.40 First 4 0.80 Second 40 0.80 First 2 0.40 Second 10 0.20 4.80
    Comparative product 7 First 4 0.80 Second 40 0.80 First 4 0.80 Second 40 0.80 First 4 0.80 Second 40 0.80 4.80
    Comparative product 8 First 4 0.80 Second 40 0.80 First 4 0.80 Second 40 0.80 First 4 0.80 Second 40 0.80 4.80
    Comparative product 9 First 4 0.80 Second 40 0.80 First 4 0.80 Second 40 0.80 First 4 0.80 Second 40 0.80 4.80
    Comparative product 10 First 4 0.80 Second 40 0.80 First 4 0.80 Second 40 0.80 First 4 0.80 Second 40 0.80 4.80
    *"First" and "Second" at the column of "Laminated structure" mean the first laminated structure and the second laminated structure of the Present product with the corresponding number in Table 7 and Table 8.
    [Table 10]
    Sample No.First laminated structureSecond laminated structure
    Average thickness Surface side/Substrate side (%)Reduction in average thicknessAverage thickness Surface side/Substrate side (%)Reduction in average thickness
    (TA1/TB1)×100(TA2/TB2)×100
    Present product 10 33 Continuous 14 Continuous
    Present product 11 33 Continuous 14 Continuous
    Present product 12 33 Continuous 14 Continuous
    Present product 13 33 Continuous 14 Continuous
    Present product 14 33 Continuous 14 Continuous
    Present product 15 33 Continuous 14 Continuous
    Present product 16 33 Continuous 14 Continuous
    Present product 17 33 Continuous 14 Continuous
    Present product 18 33 Continuous 14 Continuous
    Present product 19 100 Not reduced 14 Continuous
    Present product 20 33 Continuous 14 Continuous
    Comparative product 7 100 Not reduced 100 Not reduced
    Comparative product 8 100 Not reduced 100 Not reduced
    Comparative product 9 100 Not reduced 100 Not reduced
    Comparative product 10 100 Not reduced 100 Not reduced


    [0105] The average thicknesses of the respective layers and the compositions of the respective layers of the obtained samples were measured in the same manner as in Example 1. These results are shown in Tables 8 to 10. In addition, Cutting test 1 and Cutting test 2 which were the same as in Example 1 were carried out by using the obtained samples to evaluate wear resistance and fracture resistance. The evaluation results are shown in Table 11.

    [0106] Evaluation standard of the processed length until the tool reaches its tool life in Cutting test 1 is as follows.
    ⊚: 11 m or more
    ○: 10.5 m or more and less than 11m
    Δ: 10 m or more and less than 10.5 m
    ×: Less than 10 m

    [0107] Evaluation standard of the processed length until the tool reaches its tool life in Cutting test 2 is as follows.
    ⊚: 5 m or more
    ○: 4.5 m or more and less than 5 m
    Δ: 4 m or more and less than 4.5 m
    ×: Less than 4 m

    [0108] An order of the evaluation is (Excellent) ⊚>○>Δ>× (Poor). The evaluation of ⊚ or ○ means that cutting performance is excellent. The results of the obtained total evaluation are shown in Table 11.
    [Table 11]
    Sample No.Cutting test 1 Wear resistance testCutting test 2 Fracture resistance test
    Tool life (m)EvaluationTool life (m)Evaluation
    Present product 10 10.2 Δ 5.5
    Present product 11 10.4 Δ 5.3
    Present product 12 10.4 Δ 5.3
    Present product 13 10.1 Δ 5.6
    Present product 14 10.1 Δ 5.3
    Present product 15 10.3 Δ 5.4
    Present product 16 10.5 5.1
    Present product 17 10.5 5.2
    Present product 18 10.2 Δ 5.3
    Present product 19 10.1 Δ 4.9
    Present product 20 10.0 Δ 5.1
    Comparative product 7 9.8 × 4.1 Δ
    Comparative product 8 9.7 × 4.0 ×
    Comparative product 9 9.8 × 4.1 Δ
    Comparative product 10 9.8 × 4.1 Δ


    [0109] From the results shown in Table 11, the results of the wear resistance test of Present products were Δ or more. The results of the wear resistance test of Present products were equal to those of Comparative products or more in the point of not evaluated to as ×. In addition, the results of the fracture resistance test of all the Present products were ⊚ or ○. The results of the fracture resistance test of Comparative products were Δ or ×. From these results, it can be understood that Present products are excellent in fracture resistance than Comparative products. From these results, it can be understood that tool lives of Present products is elongated. As can be seen from these results, according to the present disclosure, fracture resistance could be improved without lowering wear resistance of the coated tool.

    [Example 3]



    [0110] Present products 21 to 27 and Comparative products 11 to 13 were prepared as follows.

    [0111] A cemented carbide corresponding to P10 with an ISO standard SEEN1203AGTN insert shape was prepared as the substrate. In the reaction vessel of an arc ion plating device, metal evaporation sources which became the compositions of the respective layers shown in Table 12 and Table 13 were arranged. According to the same preparation method as in Example 1, the samples having layer constitutions shown in Tables 13, 14 and 16 were prepared.
    [Table 12]
    Sample No.First laminated structureSecond laminated structure
    LAYER A1LAYER B1LAYER A2LAYER B2
    CompositionCompositionCompositionComposition
    Present product 21 (Ti0.50Al0.50)N (Ti0.67Al0.33)N (Ti0.50Al0.50)N (Ti0.67Al0.33)N
    Present product 22 Ti0.50Al0.50)N Ti0.67Al0.33)N (Ti0.50Al0.50)N (Ti0.67Al0.33)N
    Present product 23 (Ti0.50Al0.50)N (Al0.50Ti0.30Cr0.20)N (Ti0.50Al0.50)N (Al0.50Ti0.30Cr0.20)N
    Present product 24 (Ti0.67Al0.33)N (Al0.50Ti0.45W0.05)N (Ti0.67Al0.33)N (Al0.50Ti0.45W0.05)N
    Present product 25 (Al0.50Cr0.50)N (Ti0.90Si0.10)N (Al0.50Cr0.50)N (Ti0.90Si0.10)N
    Present product 26 (Ti0.50Al0.50)N (Al0.50Ti0.45Nb0.05)N (Ti0.50Al0.50)N (Al0.50Ti0.45Nb0.05)N
    Present product 27 (Ti0.50Al0.50)N (Ti0.40Al0.30Cr0.20Si0.10)N (Ti0.50Al0.50)N (Ti0.40Al0.30Cr0.20Si0.10)N
    [Table 13]
    Sample No.Coating layer
    Alternately laminated layersTotal thickness (µm)
    CompositionFirst layerSecond layerThird layer
    Average thicknessLAYER X and LAYER YAverage thicknessLAYER X and LAYER YAverage thicknessLAYER X and LAYER Y
    LAYER XLAYER YLAYER XLAYER YLAYER XLAYER YLAYER XLAYER Y
    (nm)(nm)Repeated times (times)(nm)(nm)Repeated times (times)(nm)(nm)Repeated times (times)
    Comparative product 11 (Ti0.50Al0.50)N (Ti0.67Al0.33)N 100 100 10 90 90 10 80 80 10 5.40
    Comparative product 12 (Ti0.67Al0.33)N (Ti0.50Al0.50)N 60 60 22 40 40 22 22 20 22 5.32
    Comparative product 13 (Ti0.67Al0.33)N (Ti0.33Al0.67)N 60 60 25 40 40 20 22 20 15 5.23
    [Table 14]
    Sample No.First layer (Substrate side)Second layerThird layerFourth layerFifth layerSixth layer (Surface side)
    First laminated structureSecond laminated structureFirst laminated structureSecond laminated structureFirst laminated structureSecond laminated structure
    LAYER A1LAYER B1LAYER A2LAYER B2LAYER A1LAYER B1LAYER A2LAYER B2LAYER A1LAYER B1LAYER A2LAYER B2
    Average thickness (nm) TD1Average thickness (nm)Average thickness (nm) TD2Average thickness (nm)Average thickness (nm)Average thickness (nm)Average thickness (nm)Average thickness (nm)Average thickness (nm)Average thickness (nm) TC1Average thickness (nm)Average thickness (nm) TC2
    Present product 21 100 100 30 30 80 80 20 20 60 60 10 10
    Present product 22 150 150 30 30 60 60 10 10 - - - -
    Present product 23 100 100 40 40 80 80 10 10 60 60 2 2
    Present product 24 200 200 30 30 80 80 20 20 60 60 10 10
    Present product 25 70 70 20 20 65 65 10 10 60 60 5 5
    Present product 26 70 70 30 30 70 70 20 20 70 70 10 10
    Present product 27 80 80 20 20 60 60 20 20 40 40 20 20
    [Table 15]
    Sample No.First laminated structureSecond laminated structure
    Average thickness of respective layers Surface side/Substrate side (%)Reduction in average thickness of respective layersAverage thickness of respective layers Surface side/Substrate side (%)Reduction in average thickness of respective layers
    (TC1/TD1)×100(TC2/TD2)×100
    Present product 21 60 Continuous 33 Continuous
    Present product 22 40 Stepwise 33 Stepwise
    Present product 23 60 Continuous 5 Stepwise
    Present product 24 30 Stepwise 33 Continuous
    Present product 25 86 Continuous 25 Stepwise
    Present product 26 100 Not reduced 33 Continuous
    Present product 27 50 Continuous 100 Not reduced
    [Table 16]
    Sample No.Coating layer
    First layer(Substrate side)Second layerThird layerFourth layerFifth layerSixth layer(Surface side)Total thickness (µm)
    Layer A1 and Layer B1Layer A2 and Layer B2Layer A1 and Layer B1Layer A2 and Layer B2Layer A1 and Layer B1Layer A2 and Layer B2
    Laminated structureRepeated times (times)Average thickness (µm) TB1Laminated structureRepeated' times (times)Average thickness (µm) TB2Laminated structureRepeated times (times)Average thickness (µm)Laminated structureRepeated! times (times)Average thickness (µm)Laminated structureRepeated times (times)Average thickness (µm) TA1Laminated structureRepeated times (times)Average thickness (µm) TA2
    Present product 21 First 6 1.20 Second 40 2.40 First 4 0.64 Second 20 0.80 First 2 0.24 Second 10 0.20 5.48
    Present product 22 First 6 1.80 Second 40 2.40 First 4 0.48 Second 20 0.40 - - - - - - 5.08
    Present product 23 First 4 0.80 Second 40 3.20 First 3 0.48 Second 30 0.60 First 2 0.24 Second 20 0.08 5.40
    Present product 24 First 8 3.20 Second 20 1.20 First 3 0.48 Second 15 0.60 First 2 0.24 Second 5 0.10 5.82
    Present product 25 First 10 1.40 Second 40 1.60 First 7 0.91 Second 30 0.60 First 3 0.36 Second 20 0.20 5.07
    Present product 26 First 6 0.84 Second 40 2.40 First 4 0.56 Second 20 0.80 First 2 0.28 Second 10 0.20 5.08
    Present product 27 First 6 0.96 Second 40 1.60 First 4 0.48 Second 35 1.40 First 2 0.16 Second 10 0.40 5.00
    *"First" and "Second" at the column of "Laminated structure" mean the first laminated structure and the second laminated structure of the Present product with the corresponding number in Table 7 and Table 8.
    [Table 17]
    Sample No.First laminated structureSecond laminated structure
    Average thickness Surface side/Substrate side (%)Reduction in average thicknessAverage thickness Surface side/Substrate side (%)Reduction in average thickness
    (TA1/TB1)×100(TA2/TB2)×100
    Present product 21 20 Continuous 8 Stepwise
    Present product 22 27 Stepwise 17 Stepwise
    Present product 23 30 Continuous 3 Continuous
    Present product 24 8 Stepwise 8 Stepwise
    Present product 25 26 Stepwise 13 Continuous
    Present product 26 33 Continuous 8 Stepwise
    Present product 27 17 Continuous 25 Stepwise


    [0112] The average thicknesses of the respective layers and the compositions of the respective layers of the obtained samples were measured in the same manner as in Example 1. These results are shown in Table 12 to 17. In addition, Cutting test 1 and Cutting test 2 which were the same as in Example 1 were carried out by using the obtained samples to evaluate wear resistance and fracture resistance. The evaluation results are shown in Table 18.

    [0113] Evaluation standard of the processed length until the tool reaches its tool life in Cutting test 1 is as follows.
    ⊚: 11 m or more
    ○: 10.5 m or more and less than 11 m
    Δ: 10 m or more and less than 10.5 m
    ×: Less than 10 m

    [0114] Evaluation standard of the processed length until the tool reaches its tool life in Cutting test 2 is as follows.
    ⊚: 5 m or more
    ○: 4.5 m or more and less than 5 m
    Δ: 4 m or more and less than 4.5 m
    ×: Less than 4 m

    [0115] An order of the evaluation is (Excellent) ⊚>○>Δ>× (Poor). The evaluation of ⊚ or ○ means that cutting performance is excellent. The results of the obtained total evaluation are shown in Table 18.
    [Table 18]
    Sample No.Cutting test 1 Wear resistance testCutting test 2 Fracture resistance test
    Tool life (m)EvaluationTool life (m)Evaluation
    Present product 21 10.1 Δ 6.1
    Present product 22 10.0 Δ 6.0
    Present product 23 10.0 Δ 6.0
    Present product 24 10.3 Δ 5.4
    Present product 25 10.1 Δ 5.1
    Present product 26 10.1 Δ 5.5
    Present product 27 10.1 Δ 5.5
    Comparative product 11 10.0 Δ 4.3 Δ
    Comparative product 12 10.2 Δ 4.1 Δ
    Comparative product 13 10.2 Δ 4.3 Δ


    [0116] From the results of Table 18, the results of the wear resistance test of Present products were Δ. The results of the wear resistance test of Present products were equal to those of Comparative products or more in the point of not evaluated to as ×. In addition, the results of the fracture resistance test of all the Present products were ⊚. The results of the fracture resistance test of Comparative products were Δ. From these results, it can be understood that Present products are excellent in fracture resistance than Comparative products. From these results, it can be understood that tool lives of Present products are elongated. As can be seen from these results, according to the present invention, fracture resistance could be improved without lowering wear resistance of the coated tool.

    [Example 4]



    [0117] Present products 28 to 30 were prepared as follows.

    [0118] A cemented carbide corresponding to P10 with an ISO standard SEEN1203AGTN insert shape was prepared as the substrate. In the reaction vessel of an arc ion plating device, metal evaporation sources which became the compositions of the respective layers shown in Table 19 were arranged. According to the same preparation method as in Example 1, the samples having layer constitutions shown in Table 20 and Table 21 were prepared.
    [Table 19]
    Sample No.Lower layerFirst laminated structureSecond laminated structureUpper layer
    LAYER A1LAYER B1LAYER A2LAYER B2
    CompositionCompositionCompositionCompositionCompositionComposition
    Present product 28 (Al0.50Ti0.30Cr 0.20)N (Ti0.50Al0.50) N (Ti0.67Al0.33) N (Ti0.50Al0.50) N (Ti0.67Al0.33) N (Al0.50Ti0.30Cr 0.20)N
    Present product 29 TiN (Ti0.50Al0.50) N (Ti0.67Al0.33) N (Ti0.50Al0.50) N (Ti0.67Al0.33) N -
    Present product 30 - (Ti0.50Al0.50) N (Ti0.67Al0.33) N (Ti0.50Al0.50) N (Ti0.67Al0.33) N (Ti0.50Al0.05) N
    [Table 20]
    Sample No.First laminated structureSecond laminated structure
    LAYER A1LAYER B1LAYER A2LAYER B2
    Average thickness (nm)Average thickness (nm)Average thickness (nm)Average thickness (nm)
    Present product 28 100 100 10 10
    Present product 29 60 60 2 2
    Present product 30 250 250 10 10
    [Table 21]
    Sample No.Coating layer
    First layer (Substrate side)Second layerThird layerFourth layerFifth layerSixth layerSeventh layerEighth (Surface side)Total thickness (µm)
    Lower layerLayer A1 and Layer B1Layer A2 and Layer B2Layer A1 and Layer B1Layer A2 and Layer B2Layer A1 and Layer B1Layer A2 and Layer B2Upper layer
    Average thickness (µm)Laminated structureRepeated times (times)Average thickness (µm)) TB1Laminated structureRepeat -ed times (times)Average thickness (µm) TB2Laminated structureRepeated times (times)Average thickness (µm)Laminated structureRepeated times (times)Average thickness (µm)Laminated structureRepeated times (times)Average thickness (µm) TA1Laminated structureRepeated times (times)Average thickness (µm) TA2Average thickness (µm)
    Present product 28 0.5 First 6 1.20 Second 50 1.00 First 4 0.80 Second 30 0.60 First 2 0.40 Second 10 0.20 0.50 5.20
    Present product 29 0.5 First 8 0.96 Second 250 1.00 First 6 0.72 Second 150 0.60 First 4 0.48 Second 50 0.20 0.00 4.46
    Present product 30 0 First 4 2.00 Second 50 1.00 First 2 1.00 Second 20 0.40 - - - - - - 0.50 4.90
    *"First" and "Second" at the column of "Laminated structure" mean the first laminated structure and the second laminated structure of the Present product with the corresponding number in Table 19 and Table 20.
    [Table 22]
    Sample No.First laminated structureSecond laminated structure
    Average thickness Surface side/Substrate side (%)Reduction in average thicknessAverage thickness Surface side/Substrate side (%)Reduction in average thickness
    (TA1/TB1)×100(TA2/TB2)×100
    Present product 28 33 Continuous 20 Continuous
    Present product 29 50 Continuous 20 Continuous
    Present product 30 50 Stepwise 40 Stepwise


    [0119] The average thicknesses of the respective layers and the compositions of the respective layers of the obtained samples were measured in the same manner as in Example 1. These results are shown in Tables 19 to 22. In addition, Cutting test 1 and Cutting test 2 which were the same as in Example 1 were carried out by using the obtained samples to evaluate wear resistance and fracture resistance. The evaluation results are shown in Table 23.

    [0120] Evaluation standard of the processed length until the tool reaches its tool life in Cutting test 1 is as follows.
    ⊚: 11 m or more
    ○: 10.5 m or more and less than 11 m
    Δ: 10 m or more and less than 10.5 m
    ×: Less than 10 m

    [0121] Evaluation standard of the processed length until the tool reaches its tool life in Cutting test 2 is as follows.
    ⊚: 5 m or more
    ○: 4.5 m or more and less than 5 m
    Δ: 4 m or more and less than 4.5 m
    ×: Less than 4 m

    [0122] An order of the evaluation is (Excellent) ⊚>○>Δ>× (Poor). The evaluation of ⊚ or ○ means that cutting performance is excellent. The results of the obtained total evaluation are shown in Table 23.
    [Table 23]
    Sample No.Cutting test 1 Wear resistance testCutting test 2 Fracture resistance test
    Tool life (m)EvaluationTool life (m)Evaluation
    Present product 28 10.2 Δ 5.3
    Present product 29 10.4 Δ 5.1
    Present product 30 10.2 Δ 5.4


    [0123] From the results of Table 23, the results of the wear resistance test of Present products were Δ. The results of the wear resistance test of Present products did not have ×. In addition, the results of the fracture resistance test of all the Present products were ⊚. From these results, it can be understood that Present products are excellent in fracture resistance. From these results, it can be understood that Present products are elongated in tool lives whereas these have the lower layer and/or the upper layer. As can be seen from these results, according to the present disclosure, fracture resistance can be improved without lowering wear resistance of the coated tool.

    UTILIZABILITY IN INDUSTRY



    [0124] According to the present invention, fracture resistance can be improved without lowering wear resistance of the coated tool. According to the present invention, tool life can be elongated than the conventional ones. Accordingly, utilizability in industry of the present invention is high.

    EXPLANATION OF REFERENCE NUMERALS



    [0125] 
    1
    Substrate
    2
    Coating layer
    3a
    First laminated structure in which the thickness is thick at the substrate side
    3b
    First laminated structure in which the thickness is thin at the surface side
    4a
    Second laminated structure in which the thickness is thick at the substrate side
    4b
    Second laminated structure in which the thickness is thin at the surface side
    5a
    Layer A1 in which the thickness is thick at the substrate side
    5b
    Layer A1 in which the thickness is thin at the surface side
    6a
    Layer B1 in which the thickness is thick at the substrate side
    6b
    Layer B1 in which the thickness is thin at the surface side
    7a
    Layer A2 in which the thickness is thick at the substrate side
    7b
    Layer A2 in which the thickness is thin at the surface side
    8a
    Layer B2 in which the thickness is thick at the substrate side
    8b
    Layer B2 in which the thickness is thin at the surface side



    Claims

    1. A coated tool which comprises

    a substrate (1), and

    a coating layer (2) formed onto a surface of the substrate,

    wherein the coating layer (2) contains a first laminated structure (3a, 3b) and a second laminated structure (4a, 4b),

    the first laminated structure (3a, 3b) and the second laminated structure (4a, 4b) are laminated alternately and continuously twice or more,

    the first laminated structure (3a, 3b) contains at least two kinds of layers (A1, B1) having different compositions, and the two kinds of the layers (A1, B1) are alternately laminated twice or more,

    an average thickness of the layers (A1, B1) contained in the first laminated structure (3a, 3b) is 60 nm or more and 500 nm or less,

    the second laminated structure (4a, 4b) contains at least two kinds of layers (A2, B2) having different compositions, and the two kinds of the layers (A2, B2) are alternately laminated twice or more,

    an average thickness of the layers (A2, B2) contained in the second laminated structure (4a, 4b) is 2 nm or more and less than 60 nm,

    the layers contained in the first laminated structure (3a, 3b) and the second laminated structure (4a, 4b) contain a compound comprising at least one metal element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Sr, Y, Sn and Bi, and at least one non-metal element selected from the group consisting of carbon, nitrogen, oxygen and boron, characterized in that

    an average thickness of the first laminated structure (3a, 3b) is 0.2 µm or more and 6 µm or less,

    an average thickness of the second laminated structure (4a, 4b) is 0.02µm or more and 6 µm or less,

    an average thickness of the whole coating layer (2) is 0.22 µm or more and 12 µm or less,

    an average thickness(es) of the first laminated structure (3a, 3b) and/or the second laminated structure (4a, 4b) is/are continuously or stepwisely reduced from the substrate side toward a surface side of the coating layer (2), wherein

    when an average thickness of the first laminated structure (3b) nearest to the surface of the coating layer (2) is made TA1, and an average thickness of the first laminated structure (3a) nearest to the substrate (1) is made TB1, then a ratio of TA1 to TB1 is 5% or more and 50% or less,

    when an average thickness of the second laminated structure (4b) nearest to the surface of the coating layer (2) is made TA2, and an average thickness of the second laminated structure (4a) nearest to the substrate (1) is made TB2, then a ratio of TA2 to TB2 is 5% or more and 50% or less,

    when an average thickness of the layers (A1, B1) contained in the first laminated structure (3b) nearest to the surface of the coating layer (2) is made TC1, and an average thickness of the layers (A1, B1) contained in the first laminated structure (3a) nearest to the substrate (1) is made TD1, then a ratio of TC1 to TD1 is 12% or more and 70% or less, and

    when an average thickness of the layers (A2, B2) contained in the second laminated structure (4b) nearest to the surface of the coating layer (2) is made TC2, and an average thickness of the layers (A2, B2) contained in the second laminated structure (4a) nearest to the substrate (1) is made TD2, then a ratio of TC2 to TD2 is 5% or more and 70% or less.


     
    2. The coated tool according to Claim 1, wherein the layers contained in the first laminated structure and the layers contained in the second laminated structure contain a compound comprising at least two metal elements selected from the group consisting of Ti, Nb, Ta, Cr, W, Al, Si, Sr and Y, and at least one non-metal element selected from the group consisting of carbon, nitrogen, oxygen and boron.
     


    Ansprüche

    1. Beschichtetes Werkzeug, das aufweist:

    ein Substrat (1); und

    eine auf einer Oberfläche des Substrats ausgebildete Überzugsschicht (2),

    wobei die Überzugsschicht (2) eine erste laminierte Struktur (3a, 3b) und eine zweite laminierte Struktur (4a, 4b) aufweist,

    wobei die erste laminierte Struktur (3a, 3b) und die zweite laminierte Struktur (4a, 4b) abwechselnd und kontinuierlich zweimal oder mehrmals laminiert sind,

    die erste laminierte Struktur (3a, 3b) mindestens zwei Arten von Schichten (A1, B1) mit unterschiedlichen Zusammensetzungen enthält, wobei die zwei Arten der Schichten (A1, B1) abwechselnd zweimal oder mehrmals laminiert sind,

    wobei eine durchschnittliche Dicke der in der ersten laminierten Struktur (3a, 3b) enthaltenen Schichten (A1, B1) 60 nm oder mehr und 500 nm oder weniger beträgt,

    die zweite laminierte Struktur (4a, 4b) mindestens zwei Arten von Schichten (A2, B2) mit unterschiedlichen Zusammensetzungen enthält, wobei die zwei Arten der Schichten (A2, B2) abwechselnd zweimal oder mehrmals laminiert sind,

    eine durchschnittliche Dicke der in der zweiten laminierten Struktur (4a, 4b) enthaltenen Schichten (A2, B2) 2 nm oder mehr und weniger als 60 nm beträgt,

    die in der ersten laminierten Struktur (3a, 3b) und in der zweiten laminierten Struktur (4a, 4b) enthaltenen Schichten eine Verbindung enthalten, die mindestens ein Metallelement aufweist, das ausgewählt ist aus der Gruppe bestehend aus Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Sr, Y, Sn und Bi, und mindestens ein Nichtmetallelement, das ausgewählt ist aus der Gruppe bestehend aus Kohlenstoff, Stickstoff, Sauerstoff und Bor,

    dadurch gekennzeichnet, dass

    eine durchschnittliche Dicke der ersten laminierten Struktur (3a, 3b) 0,2 µm oder mehr und 6 µm oder weniger beträgt;

    eine durchschnittliche Dicke der zweiten laminierten Struktur (4a, 4b) 0,02 µm oder mehr und 6 µm oder weniger beträgt;

    eine durchschnittliche Dicke der gesamten Überzugsschicht (2) 0,22 µm oder mehr und 12 µm oder weniger beträgt;

    eine durchschnittliche Dicke (durchschnittliche Dicken) der ersten laminierten Struktur (3a, 3b) und/oder der zweiten laminierten Struktur (4a, 4b) von der Substratseite in Richtung zu einer Oberflächenseite der Überzugsschicht (2) kontinuierlich oder schrittweise abnimmt (abnehmen), wobei

    wenn eine durchschnittliche Dicke der ersten laminierten Struktur (3b), die der Oberfläche der Überzugsschicht (2) am nächsten liegt, als TA1 bezeichnet wird und eine durchschnittliche Dicke der ersten laminierten Struktur (3a), die dem Substrat (1) am nächsten liegt, als TB1 bezeichnet wird, ein Verhältnis zwischen TA1 und TB1 5% oder mehr und 50% oder weniger beträgt,

    wenn eine durchschnittliche Dicke der zweiten laminierten Struktur (4b), die der Oberfläche der Überzugsschicht (2) am nächsten liegt, als TA2 bezeichnet wird und eine durchschnittliche Dicke der zweiten laminierten Struktur ( 4a), die dem Substrat (1) am nächsten liegt, als TB2 bezeichnet wird, ein Verhältnis zwischen TA2 und TB2 5% oder mehr und 50% oder weniger beträgt,

    wenn eine durchschnittliche Dicke der Schichten (A1, B1), die in der ersten laminierten Struktur (3b) enthalten sind, die der Oberfläche der Überzugsschicht (2) am nächsten liegt, als TC1 bezeichnet wird und eine durchschnittliche Dicke der Schichten (A1, B1), die in der ersten laminierten Struktur (3a) enthalten sind, die dem Substrat (1) am nächsten liegt, als TD1 bezeichnet wird, ein Verhältnis zwischen TC1 und TD1 12% oder mehr und 70% oder weniger beträgt, und

    wenn eine durchschnittliche Dicke der Schichten (A2, B2), die in der zweiten laminierten Struktur (4b) enthalten sind, die der Oberfläche der Überzugsschicht (2) am nächsten liegt, als TC2 bezeichnet wird und eine durchschnittliche Dicke der Schichten (A2, B2), die in der zweiten laminierten Struktur (4a) enthalten sind, die dem Substrat (1) am nächsten liegt, als TD2 bezeichnet wird, ein Verhältnis zwischen TC2 und TD2 5% oder mehr und 70% oder weniger beträgt.


     
    2. Beschichtetes Werkzeug nach Anspruch 1, wobei die in der ersten laminierten Struktur enthaltenen Schichten und die in der zweiten laminierten Struktur enthaltenen Schichten eine Verbindung enthalten, die mindestens zwei Metallelemente, die ausgewählt sind aus der Gruppe bestehend aus Ti, Nb, Ta, Cr, W, Al, Si, Sr und Y, und mindestens ein Nichtmetallelement aufweisen, das ausgewählt ist aus der Gruppe bestehend aus Kohlenstoff, Stickstoff, Sauerstoff und Bor.
     


    Revendications

    1. Outil revêtu qui comprend
    un substrat (1), et
    une couche de revêtement (2) formée sur une surface du substrat,
    dans lequel la couche de revêtement (2) contient une première structure stratifiée (3a, 3b) et une seconde structure stratifiée (4a, 4b),
    la première structure stratifiée (3a, 3b) et la seconde structure stratifiée (4a, 4b) sont stratifiées de manière alternée et continue deux fois ou plus,
    la première structure stratifiée (3a, 3b) contient au moins deux types de couches (A1, B1) présentant des compositions différentes, et les deux types des couches (A1, B1) sont stratifiés de manière alternée deux fois ou plus,
    une épaisseur moyenne des couches (A1, B1) contenues dans la première structure stratifiée (3a, 3b) est de 60 nm ou supérieure et 500 nm ou inférieure,
    la seconde structure stratifiée (4a, 4b) contient au moins deux types de couches (A2, B2) présentant des compositions différentes, et les deux types des couches (A2, B2) sont stratifiés de manière alternée deux fois ou plus,
    une épaisseur moyenne des couches (A2, B2) contenues dans la seconde structure stratifiée (4a, 4b) est de 2 nm ou supérieure et inférieure à 60 nm,
    les couches contenues dans la première structure stratifiée (3a, 3b) et la seconde structure stratifiée (4a, 4b) contiennent un composé comprenant au moins un élément de métal choisi dans le groupe consistant en Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si, Sr, Y, Sn et Bi, et au moins un élément de non-métal choisi dans le groupe consistant en carbone, azote, oxygène et bore, caractérisé en ce que
    une épaisseur moyenne de la première structure stratifiée (3a, 3b) est de 0,2 µm ou supérieure et de 6 µm ou inférieure,
    une épaisseur moyenne de la seconde structure stratifiée (4a, 4b) est de 0,02 µm ou supérieure et de 6 µm ou inférieure,
    une épaisseur moyenne de la couche de revêtement entière (2) est de 0,22 µm ou supérieure et de 12 µm ou inférieure,
    une(des) épaisseur(s) moyenne(s) de la première structure stratifiée (3a, 3b) et/ou la seconde structure stratifiée (4a, 4b) est/sont réduite(s) en continue ou par étape à partir du côté de substrat vers un côté de surface de la couche de revêtement (2), dans lequel
    lorsqu'une épaisseur moyenne de la première structure stratifiée (3b) la plus proche de la surface de la couche de revêtement (2) est TA1, et une épaisseur moyenne de la première structure stratifiée (3a) la plus proche du substrat (1) est TB1, alors un rapport de TA1 à TB1 est de 5 % ou supérieur et de 50 % ou inférieur,
    lorsqu'une épaisseur moyenne de la seconde structure stratifiée (4b) la plus proche de la surface de la couche de revêtement (2) est TA2, et une épaisseur moyenne de la seconde structure stratifiée (4a) la plus proche du substrat (1) est TB2, alors un rapport de TA2 à TB2 est de 5 % ou supérieur et de 50 % ou inférieur,
    lorsqu'une épaisseur moyenne des couches (A1, B1) contenues dans la première structure stratifiée (3b) la plus proche de la surface de la couche de revêtement (2) est TC1, et une épaisseur moyenne des couches (A1, B1) contenues dans la première structure stratifiée (3a) la plus proche du substrat (1) est TD1, alors un rapport de TC1 à TD1 est de 12 % ou supérieur et de 70 % ou inférieur, et
    lorsqu'une épaisseur moyenne des couches (A2, B2) contenues dans la seconde structure stratifiée (4b) la plus proche de la surface de la couche de revêtement (2) est TC2, et une épaisseur moyenne des couches (A2, B2) contenues dans la seconde structure stratifiée (4a) la plus proche du substrat (1) est TD2, alors un rapport de TC2 à TD2 est de 5 % ou supérieur et de 70 % ou inférieur.
     
    2. Outil revêtu selon la revendication 1, dans lequel les couches contenues dans la première structure stratifiée et les couches contenues dans la seconde structure stratifiée contiennent un composé comprenant au moins deux éléments de métaux choisis dans le groupe consistant en Ti, Nb, Ta, Cr, W, Al, Si, Sr et Y, et au moins un élément de non-métal choisi dans le groupe consistant en carbone, azote, oxygène et bore.
     




    Drawing








    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description