MATRIX FOR A HARD COMPOSITE

Description

BACKGROUND OF THE INVENTION

[0001] The invention pertains to a method of forming a matrix for a hard composite wherein the hard composite can be useful as a cutter or a wear member. Moreover, the invention pertains to a diamond composite comprising a matrix composed of carbide-based particulates bonded together by an infiltrant metal with one or more discrete diamond-based elements held therein. It should be understood that the diamond-based element could comprise a discrete-diamond composite or polycrystalline diamond composite having a substrate with a layer of polycrystalline diamond thereon. Some types of tungsten carbide that are appropriate for use in matrix tools include a macrocrystalline tungsten carbide, a crushed sintered cemented macrocrystalline tungsten carbide having a binder metal, and a crushed cast tungsten carbide.

[0002] Referring to the macrocrystalline tungsten carbide, this material is essentially stoichiometric WC which is, for the most part, in the form of single crystals. Some large crystals of macrocrystalline tungsten carbide are bicrystals. U.S. Patent No. 3,379,503 to McKenna for a PROCESS FOR PREPARING TUNGSTEN MONOCARBIDE, assigned to the assignee of the present patent application, discloses a method of making macrocrystalline tungsten carbide. U.S. Patent No. 4,834,963 to Terry et al. for MACROCRYSTALLINE TUNGSTEN MONOCARBIDE POWDER AND PROCESS FOR PRODUCING, assigned to the assignee of the present patent application, also discloses a method of making macrocrystalline tungsten carbide.

[0003] Referring to the crushed sintered cemented macrocrystalline tungsten carbide, this material comprises small particles of tungsten carbide bonded together in a metal matrix. For this material as used in this patent application, the crushed sintered cemented macrocrystalline tungsten carbide with a binder (either cobalt or nickel) is made by mixing together WC particles, Co or Ni powder and a lubricant. This mixture is pelletized, sintered, cooled, and then crushed. The pelletization does not use pressure, but instead, during the mixing of the WC particles and cobalt, the blades of the mixer cause the mixture of WC and cobalt (or nickel) to ball up into pellets.

[0004] Referring to crushed cast tungsten carbide, tungsten forms two carbides; namely, WC and W₂C. There can be a continuous range of compositions therebetween. An eutectic mixture is about 4.5 weight percent carbon. Cast tungsten carbide commercially used as a matrix powder typically has a hypoeutectic carbon content of about 4 weight percent. Cast tungsten carbide is typically frozen from the molten state and comminuted to the desired particle size.

[0005] In the past, there have been hard composites comprised of a matrix and discrete hard elements held therein. In the typical case, the matrix comprised carbide-based particulates bonded together by an infiltrant metal and the hard elements comprised diamond-based material.

[0006] Referring to the carbide-based particulates, one example of the carbide-based component contains about 67.10 weight percent macrocrystalline tungsten carbide having the following size distribution: between 18.0 and 22.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -80 +120 mesh (the mesh size is made according to ASTM Standard E-11-70, and corresponds to greater than 125 micrometers and less than or equal to 177 micrometers), between 25.0 to 30.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -120 +170 mesh (greater than 88 micrometers and less than or equal to 125 micrometers), between 29.0 weight percent and 33.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -170 +230 mesh (greater than 63 micrometers and less than or equal to 88 micrometers), between 18.0 weight percent and 22.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -230 +325 mesh (greater than 44 micrometers and less than or equal to 63 micrometers), and up to 5.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -325 mesh (less than or equal to 44 micrometers). The matrix further contains about 30.90 weight percent crushed cast tungsten carbide particles having a size of -325 mesh (less than or equal to 44 micrometers), 1.00 weight percent iron that has an average particle diameter of between 3 micrometers and 5 micrometers, and 1.00 weight percent grade 4600 steel having a particle size of -325 mesh (less than or equal to 44 micrometers).

[0007] The 4600 grade steel has the following nominal composition (weight percent): 1.57 weight percent nickel; 0.38 weight percent manganese; 0.32 weight percent silicon; 0.29 weight percent molybdenum; 0.06 weight percent carbon; and balance iron.

[0008] Another example of the carbide-based component comprises about 65 weight percent of macrocrystalline tungsten carbide having a particle size of -80 +325 mesh (greater than 44 micrometers and less than or equal to 177 micrometers), 27.6 weight percent tungsten carbide rod milled to an average particle size of 4 to 6 micrometers with superfines removed, 2.8 weight percent tungsten having a particle size of -325 mesh (less than or equal to 44 micrometers), 2.8 weight percent 4600 grade steel having a particle size of -140 mesh (less than or equal to 105 micrometers), and 1.8 weight percent of iron having a particle size of -325 mesh (less than or equal to 44 micrometers).

[0009] Another example of a carbide-based particulate component comprises 68 weight percent macrocrystalline tungsten carbide having a size of -80 +325 mesh (greater than 44 micrometers and less than or equal to 177 micrometers); 15 weight percent of macrocrystalline tungsten carbide having a size of -325 mesh (less than or equal to 44 micrometers); 15 weight percent of crushed cast tungsten carbide having a size of -325 mesh (less than or equal to 44 micrometers); and 2 weight percent nickel having a size of -325 mesh (less than or equal to 44 micrometers). This nickel is INCO type 123 from International Nickel Company and is a singular spike covered regular shaped powder. The chemical analysis and physical characteristics available from commercial literature reveal the following: The chemical analysis shows a composition of: 0.1 max. carbon, 0.15 max. oxygen, 0.001 max. sulfur, 0.01 max. iron, and balance nickel. The average particle size is 3-7 micrometers (Fisher Subsieve Size), the apparent density is 1.8-2.7 grams/cc, and the specific surface area is 0.34-0.44 m²/g.

[0010] Another example of a carbide-based particulate component comprises 64 weight percent macrocrystalline tungsten carbide having a size of -80 +325 mesh (greater than 44 micrometers and less than or equal to 177 micrometers); 14 weight percent of macrocrystalline tungsten carbide having a size of -325 mesh (less than or equal to 44 micrometers); 14 weight percent of crushed cast tungsten carbide having a size of -325 mesh (less than or equal to 44 micrometers); and 8 weight percent nickel having a size of -200 mesh (less than or equal to 74 micrometers).

[0011] Still another example of a particulate component comprises a 67.0 weight percent crushed cast tungsten carbide having a particle size distribution as follows: between 18.0 and 22.0 weight percent of the crushed cast tungsten carbide particles have a size of -80 +120 mesh (greater than 125 micrometers and less than or equal to 177 micrometers), between 25.0 to 30.0 weight percent of the crushed cast tungsten carbide particles have a size of -120 +170 mesh (greater than 88 micrometers and less than or equal to 125 micrometers), between 29.0 weight percent and 33.0 weight percent of the crushed cast tungsten carbide particles have a size of -170 +230 mesh (greater than 63 micrometers and less than or equal to 88 micrometers), between 18.0 weight percent and 22.0 weight percent of the crushed cast tungsten carbide particles have a size of -230 +325 mesh (greater than 44 micrometers and less than or equal to 63 micrometers), and up to 5.0 weight percent of the crushed cast tungsten carbide particles have a size of -325 mesh (less than or equal to 44 micrometers). The component further has 31.0 weight percent crushed cast tungsten carbide having a particle size of -325 mesh (less than or equal to 44 micrometers), 1.0 weight percent iron having a particle size of -325 mesh (less than or equal to 44 micrometers), and 1.0 weight percent 4600 steel having a particle size of -325 mesh (less than or equal to 44 micrometers).

[0012] One example of a suitable infiltrant comprises 63-67 weight percent copper, 14-16 weight percent nickel, and 19-21 weight percent zinc. This material has a specific gravity of 8.5 g/cc and has a melting point of 1100 °F. This infiltrant is used in 1/32nd inch by 5/16ths inch granules. This alloy is identified as MACROFIL 65 by applicants' assignee, and this designation will be used in this application.

[0013] Another example of a suitable infiltrant has a nominal composition of 52.7 weight percent copper, 24.0 weight percent manganese, 15.0 weight percent nickel, 8.0 weight percent zinc, .15 weight percent boron, and .15 weight percent silicon with traces of lead, tin and iron. This infiltrant is sold by Belmont Metals Inc., 330 Belmont Avenue, Brooklyn, New York 11207 under the name designation "VIRGIN binder 4537D" in 1 inch by 1/2 inch by 1/2 inch chunks. This alloy is identified as MACROFIL 53 by applicants' assignee, and this designation will be used in this application.

[0014] WO-A-92/14853 discloses a process for forming a macrocomposite having improved thermal fatigue resistance comprising the steps of mixing a tool steel microcomposite alloy powder and a carbide microcomposite powder to form a powder mass in a manner that powders are generally well distributed in that mass, and heating a hermetically sealed portion of said mass until said mass is diffusion bonded into a macrocomposite having a tool steel matrix and carbide islands dispersed in said matrix. The carbide can be a tungsten carbide cermet having a particle size of 50 to 100 micrometers.

[0015] FR-A-1320270 discloses a method of forming a matrix by heating a matrix powder in the presence of an infiltrant, wherein the matrix powder consists of cemented tungsten carbide particles having a particle size of between 1.27 and 6.35 mm, and a powder mixture of tungsten carbide and nickel, the powder having a particle size of less than 149 micrometers, preferably less than 89 micrometers. The infiltrant is a Cu-Ni alloy.

[0016] While the earlier matrices for a hard composite have performed in a satisfactory fashion, it would be desirable to provide an improved matrix for a hard composite having improved properties. These properties include impact strength, transverse rupture strength, hardness, abrasion resistance, and erosion resistance. It would also be desirable to provide an improved hard composite that uses the improved matrix material. It would still further be desirable to provide a tool member that includes a tool shank with the improved hard composite affixed thereto wherein the tool member could be used, for example, in conjunction with an oil well drill bit.

SUMMARY OF THE INVENTION

[0017] It is an object of the invention to provide an improved matrix powder for a hard composite comprising one or more discrete hard elements held in a matrix composed of carbide-based particulates bonded together by an infiltrant metal wherein the matrix has improved overall properties. It is contemplated that the hard composite could be used in cutting and drilling applications, and that the matrix powder and infiltrant without the hard element could be used in wear applications.

[0018] It is another object of the invention to provide an improved hard composite comprising a plurality of discrete hard elements, such a diamond or polycrystalline diamond composite elements, held in a matrix composed of carbide-based particulates bonded together by an infiltrant metal that has improved impact strength.

[0019] It is still another object of the invention to provide an improved hard composite comprising a plurality of discrete hard elements, such as diamond or polycrystalline diamond composite elements, held in a matrix composed of carbide-based particulates bonded together by an infiltrant metal that has improved. transverse rupture strength.

[0020] It is an object of the invention to provide an improved hard composite comprising a plurality of discrete hard elements, such as diamond or polycrystalline diamond composite elements, held in a matrix composed of carbide-based particulates bonded together by an infiltrant metal that has improved hardness.

[0021] It is another object of the invention to provide an improved hard composite comprising a plurality of discrete hard elements, such as diamond or polycrystalline diamond composite elements, held in a matrix composed of carbide-based particulates bonded together by an infiltrant metal that has improved erosion resistance properties.

[0022] In one form thereof the invention is a method of forming a matrix for a hard composite, the method comprising the steps of heating a matrix powder in the presence of an infiltrant. The matrix powder comprises at least 25 weight percent of crushed sintered cemented tungsten carbide particles having a particle size of -80+400 mesh (greater than 37 micrometers and less than or equal to 177 micrometers). The composition of the crushed sintered cemented tungsten carbide comprises between about 5 weight percent and about 20 weight percent binder metal and between about 80 weight percent and about 95 weight percent tungsten carbide.

[0023] In still another form thereof, the invention is a diamond composite member which includes a support and a diamond composite affixed to the support. The diamond composite comprises a matrix which includes a mass of particles held together by an infiltrant. The mass of particles is formed by heating a powder mixture in the presence of an infiltrant. The powder mixture comprises at least 25 weight percent of crushed sintered cemented tungsten carbide particles having a particle size of -80+400 mesh (greater than 37 micrometers and less than or equal to 177 micrometers). The composition of the crushed sintered cemented tungsten carbide comprises between about 5 weight percent and about 20 weight percent binder metal and between about 80 weight percent and about 95 weight percent tungsten carbide.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following is a brief description of the drawings which form a part of this patent application:

FIG. 1 is a schematic view of the assembly used to make a product comprising a tool shank with one embodiment of the discrete diamonds bonded thereto; and

FIG. 2 is a schematic view of the assembly used to make a product comprising a tool shank with another embodiment of the diamond composite bonded thereto; and

FIG. 3 is a perspective view of a tool drill bit that incorporates the present invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

[0025] Referring to FIG. 1, there is illustrated a schematic of the assembly used to manufacture a product using the diamond as part of the present invention. The typical product is a drill head. As will become apparent, the drill head has a shank. Cutter elements, such as the discrete diamonds are bonded to the bit head with the metal matrix. Although the method by which the shank is affixed to the drill line may vary, one common method is to provide threads on the shank so that the shank threadedly engages a threaded bore in the drill line. Another way is to weld the shank to the drill line.

[0026] The production assembly includes a carbon, such as graphite, mold, generally designated as 10, having a bottom wall 12 and an upstanding wall 14. The mold 10 defines a volume therein. The assembly further includes a top member 16 which fits over the opening of the mold 10. It should be understood that the use of the top number 16 is optional depending upon the degree of atmospheric control one desires.

[0027] A steel shank 24 is positioned within the mold before the powder is poured therein. A portion of the steel shank 24 is within the powder mixture 22 and another portion of the steel shank 24 is outside of the mixture 22. Shank 24 has threads 25 at one end thereof, and grooves 25A at the other end thereof.

[0028] Referring to the contents of the mold, there are a plurality of discrete diamonds 20 positioned at selected positions within the mold so as to be at selected positions on the surface of the finished product. The matrix powder 22 is a carbide-based powder which is poured into the mold 10 so as to be adjacent to the diamonds 20. The composition of the matrix powder 22 will be set forth hereinafter.

[0029] Once the diamonds 20 have been set and the matrix powder 22 poured into the mold, infiltrant alloy 26 is positioned adjacent to the powder mixture 22 in the mold 10. Then the top 16 is positioned over the mold, and the mold is placed into a furnace and heated to approximately 2200 °F (1177 °C) so that the infiltrant 26 melts and infiltrates the powder mass. The result is an end product wherein the infiltrant bonds the powder together, the matrix holds the diamonds therein, and the composite is bonded to the steel shank.

[0030] Referring to FIG. 2, there is illustrated a schematic of the assembly used to manufacture a second type of product using the diamond composites as part of the present invention. The assembly includes a carbon, such as graphite, mold, generally designated as 30, having a bottom wall 32 and an upstanding wall 34. The mold 30 defines a volume therein. The assembly further includes a top member 36 which fits over the opening of the mold 30. It should be understood that the use of the top member 36 is optional depending upon the degree of atmospheric control one desires.

[0031] A steel shank 42 is positioned within the mold before the powder mixture is poured therein. A portion of the steel shank 42 is within the powder mixture 40 and another portion of the steel shank 42 is outside of the mixture. The shank 42 has grooves 43 at the end that is within the powder mixture.

[0032] Referring to the contents of the mold 30, there are a plurality of carbon (graphite) blanks 38 positioned at selected positions within the mold so as to be at selected positions on the surface of the finished product. The matrix powder 40 is a carbide-based powder which is poured into the mold 30 so as to be adjacent to the carbon (graphite) blanks 38. The composition of the matrix powder 40 will be set forth hereinafter.

[0033] Once the carbon (graphite) blanks 38 have been set and the matrix powder 40 poured into the mold 30, Infiltrant alloy 44 is positioned adjacent to the powder mixture in the mold. Then the top 36 is positioned over the mold, and the mold is placed into a furnace and heated to approximately 2200 °F (1177 °C) so that the infiltrant melts and infiltrates the powder mass. The result is an intermediate product wherein the infiltrant bonds the powder together, also bonding the powder mass to the steel shank, and the carbon (graphite) blanks define recesses in the surface of the infiltrated mass.

[0034] The carbon (graphite) blanks are removed from bonded mass and a diamond composite insert, having a shape like that of the carbon (graphite) blank, is brazed into the recess to form the end product. Typically, the diamond composite drill head has a layer of discrete diamonds along the side.

[0035] Referring to FIG. 3, there is illustrated therein a portion of a tool, generally designated as 50. The tool 50 has a forwardly facing surface to which are bonded discrete diamond elements 52.

COMPARATIVE EXAMPLES

[0036] The following comparative examples were made and tested and the test results are presented below.

[0037] Comparative Example A comprises a powder matrix mixture having a composition and size distribution as follows: about 67.10 weight percent macrocrystalline tungsten carbide having the following size distribution: between 18.0 and 22.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -80 +120 mesh (greater than 125 micrometers and less than or equal to 177 micrometers) between 25.0 to 30.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -120 +170 mesh (greater than 88 micrometers and less than or equal to 125 micrometers), between 29.0 weight percent and 33.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -170 +230 mesh (greater than 63 micrometers and less than or equal to 88 micrometers), between 18.0 weight percent and 22.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -230 +325 mesh (greater than 44 micrometers and less than or equal to 63 micrometers), and up to 5.0 weight percent of the macrocrystalline tungsten carbide particles have a size of -325 mesh (less than or equal to 44 micrometers). The matrix further contains about 30.9 weight percent crushed cast tungsten carbide particles having a size of -325 mesh (less than or equal to 44 micrometers), 1.00 weight percent iron and has an average particle diameter of between 3 micrometers and 5 micrometers, and 1.00 weight percent grade 4600 steel having a particle size of -325 mesh (less than or equal to 44 micrometers). The 4600 grade steel has the following nominal composition (weight percent): 1.57 weight percent nickel; 0.38 weight percent manganese; 0.32 weight percent silicon; 0.29 weight percent molybdenum; 0.06 weight percent carbon; and balance iron.

[0038] The infiltrant was MACROFIL 53. The composition of the MACROFIL 53 is set forth above. This powder mixture was placed in a mold along with MACROFIL 53 infiltrant, and heated at about 2200 °F (1177 °C) until the infiltrant had adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

[0039] Comparative Example B comprises a powder matrix mixture having a composition and size distribution as follows: about 68 weight percent macrocrystalline tungsten carbide having a size of -80 +325 mesh (greater than 44 micrometers and less than or equal to 177 micrometers); 15 weight percent of macrocrystalline tungsten carbide having a size of -325 mesh (less than or equal to 44 micrometers); 15 weight percent of crushed cast tungsten carbide having a size of -325 mesh (less than or equal to 44 micrometers); and 2 weight percent nickel having a size of -325 mesh (less than or equal to 44 micrometers). This nickel is INCO type 123 from International Nickel Company and is a singular spike covered regular shaped powder. The chemical analysis and physical characteristics available from commercial literature reveal the following: The chemical analysis shows a composition of: 0.1 max. carbon, 0.15 max. oxygen, 0.001 max. sulfur, 0.01 max. iron, and balance nickel. The average particle size is 3-7 micrometers (Fisher Subsieve Size), the apparent density is 1.8-2.7 grams/cc, and the specific surface area is 0.34-0.44 m²/g.

[0040] The infiltrant was MACROFIL 53. The composition of the MACROFIL 53 is set forth above. This powder mixture was placed in a mold along with MACROFIL 53 infiltrant, and heated at about 2200 °F (1177 °C) until the infiltrant had adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

[0041] Comparative Example C comprises a powder matrix mixture having a composition and size distribution as follows: about 67.0 weight percent crushed cast tungsten carbide having a particle size distribution as follows: between 18.0 and 22.0 weight percent of the crushed cast tungsten carbide particles have a size of -80 +120 mesh (greater than 125 micrometers and less than or equal to 177 micrometers), between 25.0 to 30.0 weight percent of the crushed cast tungsten carbide particles have a size of -120 +170 mesh (greater than 88 micrometers and less than or equal to 125 micrometers), between 29.0 weight percent and 33.0 weight percent of the crushed cast tungsten carbide particles have a size of -170 +230 mesh (greater than 63 micrometers and less than or equal to 88 micrometers), between 18.0 weight percent and 22.0 weight percent of the crushed cast tungsten carbide particles have a size of -230 +325 mesh (greater than 44 micrometers and less than or equal to 63 micrometers), and up to 5.0 weight percent of the crushed cast tungsten carbide particles have a size of -325 mesh (less than or equal to 44 micrometers). The component further has 31.0 weight percent crushed cast tungsten carbide having a particle size of -325 mesh (less than or equal to 44 micrometers), 1.0 weight percent iron having a particle size of -325 mesh (less than or equal to 44 micrometers), and 1.0 weight percent 4600 steel having a particle size of -325 mesh (less than or equal to 44 micrometers).

[0042] The infiltrant was MACROFIL 53. The composition of the MACROFIL 53 is set forth above. This powder mixture was placed in a mold along with MACROFIL 53 infiltrant, and heated at about 2200 °F (1177 °C) until the infiltrant had adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

[0043] Comparative Example D comprises a powder matrix mixture having a composition and size distribution as follows: about 64 weight percent macrocrystalline tungsten carbide having a size of -80 +325 mesh (greater than 44 micrometers and less than or equal to 177 micrometers); 14 weight percent of macrocrystalline tungsten carbide having a size of -325 mesh (less than or equal to 44 micrometers); 14 weight percent of crushed cast tungsten carbide having a size of -325 mesh (less than or equal to 44 micrometers); and 8 weight percent nickel having a size of -200 mesh (less than or equal to 74 micrometers). This nickel is INCO type 123 from International Nickel Company and is a singular spike covered regular shaped powder. The chemical analysis and physical characteristics available from commercial literature reveal the following: The chemical analysis shows a composition of: 0.1 max. carbon, 0.15 max. oxygen, 0.001 max. sulfur, 0.01 max. iron, and balance nickel. The average particle size is 3-7 micrometers (Fisher Subsieve Size), the apparent density is 1.8-2.7 grams/cc, and the specific surface area is 0.34-0.44 m²/g.

[0044] The infiltrant was MACROFIL 53. The composition of the MACROFIL 53 is set forth above. This powder mixture was placed in a mold along with MACROFIL 53 infiltrant, and heated at about 2200 °F (1177 °C) until the infiltrant had adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

Actual Examples

[0045] The following actual examples of the present invention have been made and tested and the test results are also set forth below.

Example No. 1

[0046] Example No. 1 comprises a powder matrix mixture having a composition and size distribution as follows: 100 weight percent of crushed sintered cemented macrocrystalline tungsten carbide particles having a particle size of -140 +325 mesh (greater than 44 micrometers and less than or equal to 105 micrometers). The composition of the cemented macrocrystalline tungsten carbide comprises 13 weight percent cobalt and 87 weight percent macrocrystalline tungsten carbide wherein the macrocrystalline tungsten carbide has an average particle size between about 5 micrometers and about 25 micrometers.

[0047] The infiltrant was MACROFIL 53. The composition of the MACROFIL 53 is set forth above. This powder mixture was placed in a mold along with MACROFIL 53 infiltrant, and heated at about 2200 °F (1177 °C) until the infiltrant had adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

Example No. 2

[0048] Example No. 2 comprises a powder mixture comprising the following: 100 weight percent of crushed sintered cemented macrocrystalline tungsten carbide particles having a particle size of -140+270 mesh (greater than 63 micrometers and less than or equal to 105 micrometers). The composition of the cemented macrocrystalline tungsten carbide comprises 6 weight percent cobalt and 94 weight percent macrocrystalline tungsten carbide wherein the tungsten carbide has an average particle size between about 5 micrometers and about 25 micrometers.

[0049] The infiltrant was MACROFIL 53. The composition of the MACROFIL 53 is set forth above. This powder mixture was placed in a mold along with MACROFIL 53 infiltrant, and heated at about 2200 °F (1177 °C) until the infiltrant had adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

Example No. 3

[0050] Example No. 3 comprises a powder mixture that has the following composition and particle size distribution:

(a) about 50.25 weight percent of the mixture is macrocrystalline tungsten carbide particles with a particle size of -80+325 mesh (greater than 44 micrometers and less than or equal to 177 micrometers); and

(b) about 25.00 weight percent of the mixture is crushed sintered cemented macrocrystalline tungsten carbide particles of a size of -120 mesh (less than or equal to 125 micrometers), and has the following composition: about 6 weight percent cobalt, a maximum of 1 weight percent iron, a maximum of 1.0 weight percent tantalum, a maximum of 1.0 weight percent titanium, a maximum of 0.5 weight percent niobium, a maximum of 0.5 weight percent of other impurities and the balance macrocrystalline tungsten carbide having an average particle size of between about 5 micrometers and about 25 micrometers; and

(c) about 23.25 weight percent of the mixture is cast tungsten carbide having a particle size of -270 mesh (less than or equal to 53 micrometers) with superfines removed;

(d) about 0.75 weight percent of the mixture is grade 4600 steel having particle size of -325 mesh (less than or equal to 44 micrometers); and

(e) about 0.75 weight percent of the mixture is iron having an average particle size of 3-5 micrometers.

[0051] This powder mixture was placed in a mold along with the MACROFIL 53 infiltrant, and heated at about 2200 °F (1177 °C) until the infiltrant adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

Example No. 4

[0052] Example No. 4 comprises a powder mixture that has the following composition and particle size distribution:

(a) about 33.50 weight percent of the mixture is macrocrystalline tungsten carbide particles with a particle size of -80+325 mesh (greater than 44 micrometers and less than or equal to 177 micrometers);

(b) about 50.00 weight percent of the mixture is crushed sintered cemented macrocrystalline tungsten carbide particles of a size of -120 mesh (less than or equal to 125 micrometers), and having the following composition: about 6 weight percent cobalt, a maximum of 1 weight percent iron, a maximum of 1.0 weight percent tantalum, a maximum of 1.0 weight percent titanium, a maximum of 0.5 weight percent niobium, a maximum of 0.5 weight percent of other impurities and the balance macrocrystalline tungsten carbide having an average particle size of between about 5 micrometers to about 25 micrometers;

(c) about 15.50 weight percent of the mixture is cast tungsten carbide having a particle size of -270 mesh (less than or equal to 53 micrometers) with the superfines removed;

(d) about 0.50 weight percent of the mixture is grade 4600 steel having a particle size of -325 mesh (less than or equal to 44 micrometers); and

(e)about 0.50 weight percent of the mixture is iron having an average particle size of 3-5 micrometers.

[0053] This powder mixture was placed in a mold along with a MACROFIL 53 infiltrant, and was heated at about 2200 °F (1177 °C) until the infiltrant adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

Example No. 5

[0054] Example No. 5 comprises a powder mixture having the following composition and particle size distribution:

(a) about 16.75 weight percent of the mixture is macrocrystalline tungsten carbide particles with a particle size of -80+325 mesh (greater than 44 micrometers and less than or equal to 177 micrometers);

(b) about 75.00 weight percent of the mixture is crushed sintered cemented macrocrystalline tungsten carbide particles of a particle size of -120 mesh (less than or equal to 125 micrometers), and, having the following composition: about 6 weight percent cobalt, a maximum of 1 weight percent iron, a maximum of 1.0 weight percent tantalum, a maximum of 1.0 weight percent titanium, a maximum of 0.5 weight percent niobium, a maximum of 0.5 weight percent of other impurities and the balance macrocrystalline tungsten carbide having an average particle size between about 5 micrometers and about 25 micrometers;

(c) about 7.75 weight percent of the mixture is cast tungsten carbide having a particle size of -270 mesh (less than or equal to 53 micrometers) with superfines removed;

(d) about 0.25 weight percent of the mixture is grade 4600 steel with a particle size of -325 mesh (less than or equal to 44 micrometers), and

(e) about 0.25 weight percent of the mixture is iron, having an average particle size of 3-5 micrometers.

[0055] This powder mixture was placed in a mold along with a MACROFIL 53 infiltrant, and heated at about 2200 °F (1177 °C) until the infiltrant adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

Example No. 6

[0056] Example No. 6 comprises a powder mixture having the following composition and particle size distribution:
   (a) about 100 weight percent of the mixture is crushed sintered cemented macrocrystalline tungsten carbide particles with a particle size of -120 mesh (less than or equal to 125 micrometers) and having the following composition: about 6 weight percent cobalt, a maximum of 1 weight percent iron, a maximum of 1.0 weight percent tantalum, a maximum of 1.0 weight percent titanium, a maximum of 0.5 weight percent niobium, a maximum of 0.5 weight percent of other impurities and the balance macrocrystalline tungsten carbide having an average particle size of between about 5 micrometers and about 25 micrometers.

[0057] This powder mixture was placed in a mold along with a MACROFIL 53 infiltrant, and was heated at about 1177°C (2200 °F) until the infiltrant had adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

Example No. 7

[0058] Example No. 7 comprises a powder mixture of 100 weight percent cemented macrocrystalline tungsten carbide having a composition of 10 weight percent nickel and 90 weight percent macrocrystalline tungsten carbide. The particle size distribution of the powder mixture comprises: 0.1 weight percent of the cemented macrocrystalline tungsten carbide having a particle size of -80+120 mesh (greater than 125 micrometers and less than or equal to 177 micrometers); 11.4 weight percent of the cemented macrocrystalline tungsten carbide having a particle size of -120+170 mesh (greater than 88 micrometers and less than or equal to 125 micrometers); 41.1 weight percent of the cemented macrocrystalline tungsten carbide having a particle size of -170+230 mesh (greater than 63 micrometers and less than or equal to 88 micrometers); 44.5 weight percent of the cemented macrocrystalline tungsten carbide having a particle size of -230+325 mesh (greater than 44 micrometers and less than or equal to 63 micrometers); and 2.9 weight percent of the cemented macrocrystalline tungsten carbide having a particle size of -325+400 mesh (greater than 37 micrometers and less than or equal to 44 micrometers).

[0059] This powder mixture was placed in a mold along with a MACROFIL 53 infiltrant, and was heated at about 1177°C (2200 °F) until the infiltrant had adequately infiltrated the powder mass so as to bond it together. The mass was then allowed to cool.

Example Nos. 8 and 9

[0060] Examples Nos. 8 and 9 are the same as Example No. 7.

[0061] To form the cemented macrocrystalline tungsten carbide for Examples Nos. 7 through 9, macrocrystalline tungsten carbide was mixed with 10 weight percent nickel and the powder mixture sintered for one hour at 1371 °C (2500°F). The sintered material was then crushed into the particle sizes set forth in Examples Nos. 7 through 9.

Test Results

[0062] Tests for impact strength were conducted according to a procedure using an impact toughness machine. The machine had a hammer which when dropped created an impact loading force on a test specimen. The load required to break the specimen and the time it took to break the specimen were used to calculate the impact strength. This test was conducted using a Dynatap instrumented drop weight tower. This test is a high strain rate three-point bend test which measures the amount of energy required to break a one-half inch diameter sample pin.

[0063] Tests for the transverse rupture strength were conducted according to a procedure where a cylindrical pin of the infiltrated material was placed in a fixture. A load was then exerted on the pin until failure. The transverse rupture strength was then calculated based upon the actual load and the dimensions of the pin specimen. Tests for hardness were conducted according to the ASTM Standard B347-85

[0064] The results of the testing for impact strength, transverse rupture strength and hardness are set forth below for the six examples and the three comparative examples.

Example No. 1
Impact Strength	4.728 ft-lbs
Transverse Rupture Strength	136 ksi
Hardness	29.2 Rockwell C

Example No. 2.
Impact Strength	6.792 ft-lbs
Transverse Rupture Strength	184 ksi
Hardness	44.8 Rockwell C

Example No. 3
Impact Strength	3.516 ft-lbs
Transverse Rupture Strength	105 ksi
Hardness	33.6 Rockwell C

Example No. 4.
Impact Strength	4.819 ft-lbs
Transverse Rupture Strength	131 ksi
Hardness	42.2 Rockwell C

Example No. 5
Impact Strength	5.222 ft-lbs
Transverse Rupture Strength	153 ksi
Hardness	44.3 Rockwell C

Example No. 6
Impact Strength	8.356 ft-lbs
Transverse Rupture Strength	162 ksi
Hardness	42.5 Rockwell C

Example No. 7
Impact Strength	9.249 ft-lbs
Transverse Rupture Strength	216 ksi
Hardness	41.7 Rockwell C

Example No. 8
Impact Strength	7.912 ft-lbs
Transverse Rupture Strength	202 ksi
Hardness	35.4 Rockwell C

Example No. 9
Impact Strength	7.421 ft-lbs
Transverse Rupture Strength	191 ksi
Hardness	36.3 Rockwell C

Example A.
Impact Strength	2.730 ft-lbs
Transverse Rupture Strength	116 ksi
Hardness	38.3 Rockwell C

Example B
Impact Strength	3.094 ft-lbs
Transverse Rupture Strength	114 ksi
Hardness	31.5 Rockwell C

Example C
Impact Strength	2.466 ft-lbs
Transverse Rupture Strength	96 ksi
Hardness	38.7 Rockwell C

Example D
Impact Strength	-- ft-lbs
Transverse Rupture Strength	128 ksi
Hardness	-- Rockwell C

[0065] The abrasion testing was done according to the Riley - Stoker method (ASTM Standard B611) using a counterbalance weight of 26 Kg. These results are set forth below:

Sample	Weight Loss (Top/Bottom)*
Example No. 1	426.5/373.9
Example No. 2	373.3/298.2
Example No. 3	427.6/423.5
Example No. 4	394.4/387.4
Example No. 5	382.7/375.1
Example No. 6	339.8/374.0
Example No. 7	344.8/ -
Example No. 8	350.4/257.2
Example No. 9	357.4/331.7
Example A	439.9/443.5
Example B	472.1/466.4
Example C	322.3/329.0
Example D	419.4/406.5

* of a coin

[0066] The units for the weight loss are grams per fifty wheel revolutions.

[0067] For the erosion test procedure, the testing consisted of subjecting coins made of the matrix material to a high pressure water plus sand abrasive stream for a set length of time and measuring the mass loss of the coin. The test parameters were set as follows:

Water Pressure	1000psi
Sand Grit Size	ASTM 50-70(fine)
Nozzle Size	#4-15 degree
Test Duration	1 minute
Impingement Angle	20 degrees

[0068] The test setup consisted of a large, high pressure water pump unit, a barrel of sand, a trigger-operated nozzle delivery system, and the hoses to connect all of these together. The procedure used for testing was to weigh the coin, place it into the blast fixture, blast it for one minute, then weight it again to measure the loss due to erosion. The scale used to weigh the coin was a Mettler balance with a resolution of 0.002 grams. The coin was cleaned and dried prior to every weighing. Two tests were done on each side of the coin.

[0069] The sand and water flow rates were also monitored. The water flow rate averaged at about 2 gallons per minute throughout the entire test. The sand flow rate averaged about 0.65 lbs./minute for the test with some noticeable increase as the testing progressed. The accuracy of the sand flow measurement was about ±0.05 lbs/minute. This test procedure follows ASTM Standard G76, except that it uses a liquid jet instead of a gas jet.

[0070] These test results have been normalized to take into account the variations in sand flow. The Weight loss is in grams.

Sample	Weight Loss (Top/Bottom)*
Example No. 1	0.25/0.19
Example No. 2	0.16/0.13
Example No. 3	0.12/0.16
Example No. 4	0.13/0.10
Example No. 5	0.11/0.13
Example No. 6	0.10/0.08
Example No. 7	-----
Example No. 8	0.05/0.04
Example No. 9	-----
Example A	0.42/0.37
Example B	0.38/0.37
Example C	0.17/0.17
Example D	0.12/0.09

* of a coin

Claims

1. A method of forming a matrix for a hard composite, the method comprising the step of heating a matrix powder in the presence of an infiltrant, characterized in that the matrix powder comprises:
   at least 25 weight percent of crushed sintered cemented tungsten carbide particles having a particle size of greater than 37 micrometers and less than or equal to 177 micrometers; and the composition of the crushed sintered cemented tungsten carbide comprising between about 5 weight percent and about 20 weight percent binder metal and between about 80 weight percent and about 95 weight percent tungsten carbide.

2. The method of claim 1 wherein the binder metal is cobalt; and the composition of the crushed sintered cemented tungsten carbide is between about 6 weight percent and about 13 weight percent cobalt and between about 87 weight percent and about 94 weight percent tungsten carbide, and the particle size of the crushed sintered cemented tungsten carbide is greater than 53 micrometers and less than or equal to 105 micrometers.

3. The method of claim 1 wherein the binder metal is cobalt; and the particle size of the crushed sintered cemented tungsten carbide is greater than 44 micrometers and less than or equal to 177 micrometers.

4. The method of claim 1 wherein the binder metal is cobalt; and the crushed sintered cemented tungsten carbide particles have the following composition: about 6 weight percent cobalt, a maximum of 1 weight percent iron, a maximum of 1.0 weight percent tantalum, a maximum of 1.0 weight percent titanium, a maximum of 0.5 weight percent niobium, a maximum of 0.5 weight percent of other impurities and the balance tungsten carbide having an average particle size of between about 5 micrometers and about 25 micrometers.

5. The method of claim 1 wherein the powder comprises about 100 weight percent crushed sintered cemented tungsten carbide particles, and the particle size of the crushed sintered cemented tungsten carbide is greater than 44 micrometers and less than or equal to 177 micrometers.

6. The method of claim 1 wherein the binder metal comprises cobalt; and the matrix powder comprises:

(a) up to about 50 weight percent of the powder being tungsten carbide particles with a particle size of greater than 44 micrometers and less than or equal to 177 micrometers;

(b) at least 25 weight percent and up to about 75 weight percent of the mixture being said crushed sintered cemented tungsten carbide particles and having the composition and the particle size according to claim 4;

(c) up to about 24 weight percent of the mixture being cast tungsten carbide having an average particle size of less than or equal to 53 micrometers; and

(d) between about 0.5 and about 1.5 weight percent of the mixture being principally iron having a particle size of between about 3 micrometers and about 5 micrometers.

7. The method of claim 6 wherein the iron component comprises between about 0.25 weight percent and about 0.75 weight percent of the mixture being grade 4600 steel having a particle size of less than or equal to 44 micrometers, and between about 0.25 weight percent and about 0.75 weight percent of the mixture being iron, having a particle size of between about 3 to about 5 micrometers.

8. The method of claim 6 wherein the tungsten carbide particles comprise about 50 weight percent of the mixture, and the crushed sintered cemented tungsten carbide particles comprise about 25 weight percent of the mixture.

9. The method of claim 6 wherein the tungsten carbide particles comprise about 34 weight percent of the mixture, and the crushed sintered cemented tungsten carbide particles comprise about 50 weight percent of the mixture.

10. The method of claim 6 wherein the tungsten carbide particles comprise about 17 weight percent of the mixture, and the crushed sintered cemented tungsten carbide particles comprise about 75 weight percent of the mixture.

11. The method of claim 1 wherein the crushed sintered cemented tungsten carbide particles comprise crushed sintered cemented macrocrystalline tungsten carbide particles.

12. The method of claim 11 wherein the matrix powder comprises about 100 weight percent crushed sintered cemented macrocrystalline tungsten carbide particles.

13. The method of claim 12 wherein the binder metal is cobalt.

14. The method of claim 13 wherein the particle size of the crushed sintered cemented macrocrystalline tungsten carbide particles is greater than 44 micrometers and less than or equal to 177 micrometers.

15. The method of claim 1 wherein the binder metal is nickel; and the composition of the crushed sintered cemented tungsten carbide is between about 6 weight percent and about 13 weight percent nickel and about 87 weight percent and about 94 weight percent tungsten carbide, and the particle size of the crushed sintered cemented tungsten carbide is greater than 53 micrometers and less than or equal to 105 micrometers.

16. The method of claim 1 wherein the binder metal is nickel; and the particle size of the crushed sintered cemented tungsten carbide is greater than 44 micrometers and less than or equal to 177 micrometers.

17. The method of claim 1 wherein the binder metal is nickel; and the crushed sintered cemented tungsten carbide particles have the following composition: about 6 weight percent nickel, a maximum of 1 weight percent iron, a maximum of 1.0 weight percent tantalum, a maximum of 1.0 weight percent titanium, a maximum of 0.5 weight percent niobium, a maximum of 0.5 weight percent of other impurities and the balance tungsten carbide having an average particle size of between about 5 micrometers and about 25 micrometers.

18. The method of claim 1 wherein the binder material is nickel; and the powder comprises about 100 weight percent crushed sintered cemented tungsten carbide particles, and the particle size of the crushed sintered cemented tungsten carbide particles is greater than 44 micrometers and less than or equal to 177 micrometers.

19. The method of claim 1 wherein the binder metal comprises nickel; and the matrix powder comprises:

(a) up to about 50 weight percent of the powder being tungsten carbide particles with a particle size of greater than 44 micrometers and less than or equal to 177 micrometers;

(b) at least 25 weight percent up to about 75 weight percent of the mixture being said crushed sintered cemented tungsten carbide particles and having the following composition: about 6 weight percent nickel, a maximum of 1 weight percent iron, a maximum of 1.0 weight percent tantalum, a maximum of 1.0 weight percent titanium, a maximum of 0.5 weight percent niobium, a maximum of 0.5 weight percent of other impurities and the balance tungsten carbide having an average particle size between about 5 micrometers and about 25 micrometers;

(c) up to about 24 weight percent of the mixture being cast tungsten carbide having an average particle size of less than or equal to 53 micrometers; and

(d) between about 0.5 and about 1.5 weight percent of the mixture being principally iron having a particle size of between about 3 micrometers and about 5 micrometers.

20. The method of claim 19 wherein the iron component comprises between about 0.25 weight percent and about 0.75 weight percent of the mixture being grade 4600 steel having a particle size of less than or equal to 44 micrometers, and between about 0.25 weight percent and about 0.75 weight percent of the mixture being iron, having a particle size of between about 3 to about 5 micrometers.

21. The method of claim 19 wherein the tungsten carbide particles comprise about 50 weight percent of the mixture, and the crushed sintered cemented tungsten carbide particles comprise about 25 weight percent of the mixture.

22. The method of claim 19 wherein the tungsten carbide particles comprise about 34 weight percent of the mixture, and the crushed sintered cemented tungsten carbide particles comprise about 50 weight percent of the mixture.

23. The method of claim 19 wherein the tungsten carbide particles comprise about 17 weight percent of the mixture, and the crushed sintered cemented tungsten carbide particles comprise about 75 weight percent of the mixture.

24. The method of claim 1 wherein the infiltrant comprises between about 50 to 70 weight percent copper, between about 10 and 20 weight percent nickel, and between about 15 and 25 weight percent zinc.

25. The method of claim 24 wherein the infiltrant comprises between about 63 and 67 weight percent copper, between about 14 and 16 weight percent nickel, and between about 19 and 21 weight percent zinc.

26. The method of claim 1 wherein the infiltrant comprises between about 45 and 60 weight percent copper, 10 to 20 weight percent nickel, between about 4 to 12 weight percent zinc, between about 18 to 30 weight percent manganese, an amount of boron and an amount of silicon.

27. The method of claim 26 wherein the infiltrant comprises about 52.7 weight percent copper, about 24 weight percent manganese, about 15 weight percent nickel, about 8 weight percent zinc, about 0.15 weight percent boron, and about 0.15 weight percent silicon.

28. A diamond composite member comprising:

a support;

a diamond composite affixed to the support;

the diamond composite comprising a matrix comprising a mass of particles held together by an infiltrant, the matrix being formed by the method according to anyone of claims 1 to 27.

Ansprüche

1. Verfahren zur Bildung einer Matrix für einen harten Verbundstoff, wobei das Verfahren den Schritt des Erwärmens eines Matrixpulvers in Gegenwart eines Durchsetzungsstoffes umfaßt, dadurch gekennzeichnet, daß das Matrixpulver wenigstens 25 Gew.-% zerkleinerte, gesinterte Wolframcarbidhartmetallteilchen einer Teilchengröße von mehr als 37 Mikrometern und weniger als oder gleich 177 Mikrometern umfaßt, wobei die Zusammensetzung des zerkleinerten, gesinterten Wolframcarbidhartmetalls etwa 5 Gew.-% bis etwa 20 Gew.-% Bindermetall und etwa 80 Gew.-% bis etwa 95 Gew.-% Wolframcarbid umfaßt.

2. Verfahren nach Anspruch 1, wobei das Bindermetall Kobalt ist und das zerkleinerte, gesinterte Wolframcarbidhartmetall aus etwa 6 Gew.-% bis etwa 13 Gew.-% Kobalt und etwa 87 Gew.-% bis etwa 94 Gew.-% Wolframcarbid zusammengesetzt ist und eine Teilchengröße von mehr als 53 Mikrometern und weniger als oder gleich 105 Mikrometern aufweist.

3. Verfahren nach Anspruch 1, wobei das Bindermetall Kobalt ist und das zerkleinerte, gesinterte Wolframcarbidhartmetall eine Teilchengröße von mehr als 44 Mikrometern und weniger als oder gleich 177 Mikrometern aufweist.

4. Verfahren nach Anspruch 1, wobei das Bindermetall Kobalt ist und die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen aus etwa 6 Gew.-% Kobalt, maximal 1 Gew.-% Eisen, maximal 1,0 Gew.-% Tantal, maximal 1,0 Gew.-% Titan, maximal 0,5 Gew.-% Niob, maximal 0,5 Gew.-% anderen Unreinheiten und zum Rest aus Wolframcarbid mit einer durchschnittlichen Teilchengröße von etwa 5 Mikrometern bis etwa 25 Mikrometern zusammengesetzt sind.

5. Verfahren nach Anspruch 1, wobei das Pulver etwa 100 Gew.-% zerkleinerte, gesinterte Wolframcarbidhartmetallteilchen umfaßt und die Teilchengröße des zerkleinerten, gesinterten Wolframcarbidhartmetalls mehr als 44 Mikrometer und weniger als oder gleich 177 Mikrometer beträgt.

6. Verfahren nach Anspruch 1, wobei das Bindermetall Kobalt umfaßt und wobei das Matrixpulver folgendes umfaßt:

(a) bis zu etwa 50 Gew.-% des Matrixpulvers sind Wolframcarbidteilchen mit einer Teilchengröße von mehr als 44 Mikrometern und weniger als oder gleich 177 Mikrometern;

(b) wenigstens 25 Gew.-% und bis zu etwa 75 Gew.-% der Mischung sind die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen, welche die Zusammensetzung und die Teilchengröße nach Anspruch 4 aufweisen;

(c) bis zu etwa 24 Gew.-% der Mischung sind Guß-Wolframcarbid einer durchschnittlichen Teilchengröße von weniger als oder gleich 53 Mikrometern; und

(d) etwa 0,5 bis etwa 1,5 Gew.-% der Mischung sind im wesentlichen Eisen mit einer Teilchengröße von etwa 3 Mikrometern bis etwa 5 Mikrometern.

7. Verfahren nach Anspruch 6, wobei die Eisenkomponente etwa 0,25 Gew.-% bis etwa 0,75 Gew.-% der Mischung umfaßt und aus Stahl der Klasse 4600 mit einer Teilchengröße von weniger als oder gleich 44 Mikrometern besteht, und etwa 0,25 Gew.-% bis etwa 0,75 Gew.-% der Mischung aus Eisen mit einer Teilchengröße von etwa 3 Mikrometern bis etwa 5 Mikrometern besteht.

8. Verfahren nach Anspruch 6, wobei die Wolframcarbidteilchen etwa 50 Gew.-% der Mischung umfassen und die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen etwa 25 Gew.-% der Mischung umfassen.

9. Verfahren nach Anspruch 6, wobei die Wolframcarbidteilchen etwa 34 Gew.-% der Mischung umfassen und die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen etwa 50 Gew.-% der Mischung umfassen.

10. Verfahren nach Anspruch 6, wobei die Wolframcarbidteilchen etwa 17 Gew.-% der Mischung umfassen und die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen etwa 75 Gew.-% der Mischung umfassen.

11. Verfahren nach Anspruch 1, wobei die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen zerkleinerte, gesinterte, makrokristalline Wolframcarbidhartmetallteilchen umfassen.

12. Verfahren nach Anspruch 11, wobei das Matrixpulver etwa 100 Gew.-% zerkleinerte, gesinterte, makrokristalline Wolframcarbidhartmetallteilchen umfaßt.

13. Verfahren nach Anspruch 12, wobei das Bindermetall Kobalt ist.

14. Verfahren nach Anspruch 13, wobei die zerkleinerten, gesinterten, makrokristallinen Wolframcarbidhartmetallteilchen eine Teilchengröße von mehr als 44 Mikrometern und weniger als oder gleich 177 Mikrometern aufweisen.

15. Verfahren nach Anspruch 1, wobei das Bindermetall Nickel ist und das zerkleinerte, gesinterte Wolframcarbidhartmetall aus etwa 6 Gew.-% bis etwa 13 Gew.-% Nickel und etwa 87 Gew.-% bis etwa 94 Gew.-% Wolframcarbid zusammengesetzt ist und eine Teilchengröße von mehr als 53 Mikrometern und weniger als oder gleich 105 Mikrometern aufweist.

16. Verfahren nach Anspruch 1, wobei das Bindermetall Nickel ist und das zerkleinerte, gesinterte Wolframcarbidhartmetall eine Teilchengröße von mehr als 44 Mikrometern und weniger als oder gleich 177 Mikrometern aufweist.

17. Verfahren nach Anspruch 1, wobei das Bindermetall Nickel ist und die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen aus etwa 6 Gew.-% Nickel, maximal 1 Gew.-% Eisen, maximal 1,0 Gew.-% Tantal, maximal 1,0 Gew.-% Titan, maximal 0,5 Gew.-% Niob, maximal 0,5 Gew.-% anderen Unreinheiten und zum Rest aus Wolframcarbid einer durchschnittlichen Teilchengröße von etwa 5 Mikrometern bis etwa 25 Mikrometern zusammengesetzt sind.

18. Verfahren nach Anspruch 1, wobei das Bindermetall Nickel ist und das Pulver etwa 100 Gew.-% zerkleinerte, gesinterte Wolframcarbidhartmetallteilchen einer Teilchengröße von mehr als 44 Mikrometern und weniger als oder gleich 177 Mikrometern umfaßt.

19. Verfahren nach Anspruch 1, wobei das Bindermetall Nickel umfaßt und wobei das Matrixpulver folgendes umfaßt:

(a) bis zu etwa 50 Gew.-% des Matrixpulvers sind Wolframcarbidteilchen mit einer Teilchengröße von mehr als 44 Mikrometern und weniger als oder gleich 177 Mikrometern;

(b) wenigstens 25 Gew.-% bis zu etwa 75 Gew.-% der Mischung sind die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen und weisen die folgende Zusammensetzung auf: etwa 6 Gew.-% Nickel, maximal 1 Gew.-% Eisen, maximal 1,0 Gew.-% Tantal, maximal 1,0 Gew.-% Titan, maximal 0,5 Gew.-% Niob, maximal 0,5 Gew.-% andere Unreinheiten und zum Rest Wolframcarbid einer durchschnittlichen Teilchengröße von etwa 5 Mikrometern bis etwa 25 Mikrometern;

(c) bis zu etwa 24 Gew.-% der Mischung sind Guß-Wolframcarbid einer durchschnittlichen Teilchengröße von weniger als oder gleich 53 Mikrometern; und

(d) etwa 0,5 bis etwa 1,5 Gew.-% der Mischung sind im wesentlichen Eisen mit einer Teilchengröße von etwa 3 Mikrometern bis etwa 5 Mikrometern.

20. Verfahren nach Anspruch 19, wobei die Eisenkomponente etwa 0,25 Gew.-% bis etwa 0,75 Gew.-% der Mischung umfaßt und aus Stahl der Klasse 4600 mit einer Teilchengröße von weniger als oder gleich 44 Mikrometern besteht, und etwa 0,25 Gew.-% bis etwa 0,75 Gew.-% der Mischung aus Eisen mit einer Teilchengröße von etwa 3 Mikrometern bis etwa 5 Mikrometern besteht.

21. Verfahren nach Anspruch 19, wobei die Wolframcarbidteilchen etwa 50 Gew.-% der Mischung umfassen und die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen etwa 25 Gew.-% der Mischung umfassen.

22. Verfahren nach Anspruch 19, wobei die Wolframcarbidteilchen etwa 34 Gew.-% der Mischung umfassen und die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen etwa 50 Gew.-% der Mischung umfassen.

23. Verfahren nach Anspruch 19, wobei die Wolframcarbidteilchen etwa 17 Gew.-% der Mischung umfassen und die zerkleinerten, gesinterten Wolframcarbidhartmetallteilchen etwa 75 Gew.-% der Mischung umfassen.

24. Verfahren nach Anspruch 1, wobei der Durchsetzungsstoff etwa 50 bis 70 Gew.-% Kupfer, etwa 10 bis 20 Gew.-% Nickel und etwa 15 bis 25 Gew.-% Zink umfaßt.

25. Verfahren nach Anspruch 24, wobei der Durchsetzungsstoff etwa 63 bis 67 Gew.-% Kupfer, etwa 14 bis 16 Gew.-% Nickel und etwa 19 bis 21 Gew.-% Zink umfaßt.

26. Verfahren nach Anspruch 1, wobei der Durchsetzungsstoff etwa 45 bis 60 Gew.-% Kupfer, 10 bis 20 Gew.-% Nickel, etwa 4 bis 12 Gew.-% Zink, etwa 18 bis 30 Gew.-% Mangan, eine gewisse Menge Bor und eine gewisse Menge Silizium umfaßt.

27. Verfahren nach Anspruch 26, wobei der Durchsetzungsstoff etwa 52,7 Gew.-% Kupfer, etwa 24 Gew.-% Mangan, etwa 15 Gew.-% Nickel, etwa 8 Gew.-% Zink, etwa 0,15 Gew.-% Bor und etwa 0,15 Gew.-% Silizium umfaßt.

28. Diamantverbundstoff-Element mit:

einem Träger, und

einem an dem Träger befestigten Diamantverbundstoff,

wobei der Diamantverbundstoff eine Matrix umfaßt, die eine mittels eines Durchsetzungsstoffes zusammengehaltene Teilchenmasse beinhaltet, wobei die Matrix durch das Verfahren nach einem der Ansprüche 1 bis 27 gebildet ist.

Revendications

1. Procédé de formation d'une matrice pour un composite dur, le procédé comprenant l'étape de chauffage d'une poudre à mouler en présence d'un produit d'infiltration, caractérisé en ce que la poudre à mouler comprend:
au moins 25% en poids de grains de carbure de tungstène cémenté fritté et broyé d'une taille de grains supérieure à 37 microns et inférieure ou égale à 177 microns; la composition du carbure de tungstène cémenté fritté et broyé comprenant entre à peu près 5 et à peu près 20% en poids de liant métallique et entre à peu près 80 et à peu près 95% en poids de carbure de tungstène.

2. Procédé selon la revendication 1, dans lequel le liant métallique est le cobalt; la composition du carbure de tungstène cémenté fritté et broyé est la suivante : entre à peu près 6 et à peu près 13% en poids de cobalt et entre à peu près 87 et à peu près 94% en poids de carbure de tungstène, et la taille de grains du carbure de tungstène cémenté fritté et broyé est supérieure à 53 microns et inférieure ou égale à 105 microns.

3. Procédé selon la revendication 1, dans lequel le liant métallique est le cobalt, et la taille de grains du carbure de tungstène cémenté fritté et broyé est supérieure à 44 microns et inférieure ou égale à 177 microns.

4. Procédé selon la revendication 1, dans lequel le liant métallique est le cobalt, et les grains de carbure de tungstène cémenté fritté et broyé ont la composition suivante : à peu près 6% en poids de cobalt, un maximum de 1 % en poids de fer, un maximum de 1,0% en poids de tantale, un maximum de 1,0% en poids de titane, un maximum de 0,5% en poids de niobium, un maximum de 0,5% en poids d'autres impuretés et le reste en carbure de tungstène d'une taille moyenne de grains comprise entre à peu près 5 et à peu près 25 microns.

5. Procédé selon la revendication 1, dans lequel la poudre comprend à peu près 100% en poids de grains de carbure de tungstène cémenté fritté et broyé, et la taille de grains du carbure de tungstène cémenté fritté et broyé est supérieure à 44 microns et inférieure ou égale à 177 microns.

6. Procédé selon la revendication 1, dans lequel le liant métallique comprend du cobalt; et la poudre à mouler comprend:

a) des grains de carbure de tungstène d'une taille de grains supérieure à 44 microns et inférieure au égale à 177 microns, qui constituent jusqu'à à peu près 50% en poids de la poudre;

b) des grains de carbure de tungstène cémenté fritté et broyé qui constituent au moins de 25 jusqu'à 75% en poids du mélange et dont la composition et la taille de grains sont selon la revendication 4;
et

c) du carbure de tungstène fondu d'une taille moyenne de grains inférieure ou égale à 53 microns, qui constitue jusqu'à à peu près 24% en poids du mélange;

d) entre à peu près 0,5 et à peu près 1,5% en poids du mélange étant principalement du fer d'une taille de grains comprise entre à peu près 3 et à peu près 5 microns.

7. Procédé selon la revendication 6, dans lequel le composant ferreux comprend de l'acier qualité 4600 d'une taille de grains inférieure ou égale à 44 microns, qui constitue entre à peu près 0,25 et à peu près 0,75% en poids du mélange, et du fer d'une taille de grains comprise entre à peu près 3 et à peu près 5 microns, qui constitue entre à peu près 0,25 et 0,75% en poids du mélange.

8. Procédé selon la revendication 6, dans lequel les grains de carbure de tungstène constituent à peu près 50% en poids du mélange, et les grains de carbure de tungstène cémenté fritté et broyé constituent à peu près 25% en poids du mélange.

9. Procédé selon la revendication 6, dans lequel les grains de carbure de tungstène constituent à peu près 34% en poids du mélange, et les grains de carbure de tungstène cémenté fritté et broyé constituent à peu près 50% en poids du mélange.

10. Procédé selon la revendication 6, dans lequel les grains de carbure de tungstène constituent à peu près 17% en poids du mélange, et les grains de carbure de tungstène cémenté fritté et broyé constituent à peu près 75% en poids du mélange.

11. Procédé selon la revendication 1, dans lequel les grains de carbure de tungstène cémenté fritté et broyé comprennent des grains de carbure de tungstène macrocristallin cémenté fritté et broyé.

12. Procédé selon la revendication 11, dans lequel la poudre à mouler comprend à peu près 100% en poids de grains de carbure de tungstène macrocristallin cémenté fritté et broyé.

13. Procédé selon la revendication 12, dans lequel le liant métallique est le cobalt.

14. Procédé selon la revendication 13, dans lequel la taille de grains des grains de carbure de tungstène macrocristallin cémenté fritté et broyé est supérieure à 44 microns et inférieure ou égale à 177 microns.

15. Procédé selon la revendication 1, dans lequel le liant métallique est le nickel; la composition du carbure de tungstène cémenté fritté et broyé est la suivante : entre à peu près 6 et à peu près 13% en poids de nickel et entre à peu près 87 et 94% en poids de carbure de tungstène, et la taille de grains du carbure de tungstène cémenté fritté et broyé est supérieure à 53 microns et inférieure ou égale à 105 microns.

16. Procédé selon la revendication 1, dans lequel le liant métallique est le nickel; la taille de grains de carbure de tungstène cémenté fritté et broyé est supérieure à 44 microns et inférieure ou égale à 177 microns.

17. Procédé selon la revendication 1, dans lequel le liant métallique est le nickel, et les grains de carbure de tungstène cémenté fritté et broyé ont la composition suivante : à peu près 6% en poids de nickel, un maximum de 1 % en poids de fer, un maximum de 1,0% en poids de tantale, un maximum de 1,0% en poids de titane, un maximum de 0,5% en poids de niobium, un maximum de 0,5% en poids d'autres impuretés et le reste en carbure de tungstène d'une taille moyenne de grains comprise entre à peu près 5 et à peu près 25 microns.

18. Procédé selon la revendication 1, dans lequel le liant métallique est le nickel, et la poudre comprend à peu près 100% en poids de grains de carbure de tungstène cémenté fritté et broyé, et la taille de grains des grains de carbure de tungstène cémenté fritté et broyé est supérieure à 44 microns et inférieure ou égale à 177 microns.

19. Procédé selon la revendication 1, dans lequel le liant métallique comprend du nickel; et la poudre à mouler comprend:

a) des grains de carbure de tungstène d'une taille de grains supérieure à 44 microns et inférieure ou égale à 177 microns, qui constituent jusqu'à à peu près 50% en poids de la poudre;

b) des grains de carbure de tungstène cémenté fritté et broyé qui constituent au moins de 25% en poids jusqu'à à peu près 75% en poids du mélange et ayant la composition suivante : à peu près 6% en poids de nickel, un maximum de 1 % en poids de fer, un maximum de 1,0% en poids de tantale, un maximum de 1,0% en poids de titane, un maximum de 0,5% en poids de niobium, un maximum de 0,5% en poids d'autres impuretés et le reste en carbure de tungstène d'une taille moyenne de grains comprise entre à peu près 5 et à peu près 25 microns;

c) du carbure de tungstène fondu d'une taille moyenne de grains inférieure ou égale à 53 microns, qui constitue jusqu'à à peu près 24% en poids du mélange;
et

d) entre à peu près 0,5 et à peu près 1,5% en poids du mélange étant principalement du fer d'une taille de grains comprise entre à peu près 3 et à peu près 5 microns.

20. Procédé selon la revendication 19 dans lequel le composant ferreux comprend de l'acier qualité 4600 d'une taille de grains inférieure ou égale à 44 microns, qui constitue entre à peu près 0,25 et à peu près 0,75% en poids du mélange, et du fer d'une taille de grains comprise entre à peu près 3 et à peu près 5 microns, qui constitue entre à peu près 0,25 et à peu près 0,75% en poids du mélange.

21. Procédé selon la revendication 19, dans lequel les grains de carbure de tungstène constituent à peu près 50% en poids du mélange, et les grains de carbure de tungstène cémenté fritté et broyé constituent à peu près 25% en poids du mélange.

22. Procédé selon la revendication 19, dans lequel les grains de carbure de tungstène constituent à peu près 34% en poids du mélange, et les grains de carbure de tungstène cémenté fritté et broyé constituent à peu près 50% en poids du mélange.

23. Procédé selon la revendication 19, dans lequel les grains de carbure de tungstène constituent à peu près 17% en poids du mélange, et les grains de carbure de tungstène cémenté fritté et broyé constituent à peu près 75% en poids du mélange.

24. Procédé selon la revendication 1, dans lequel le produit d'infiltration comprend entre à peu près 50 et 70% en poids de cuivre, entre à peu près 10 et 20% en poids de nickel et entre à peu près 15 et 25 % en poids de zinc.

25. Procédé selon la revendication 24, dans lequel le produit d'infiltration comprend entre à peu près 63 et 67% en poids de cuivre, entre à peu près 14 et 16% en poids de nickel et entre à peu près 19 et 21 % en poids de zinc.

26. Procédé selon la revendication 1, dans lequel le produit d'infiltration comprend entre à peu près 45 et 60% en poids de cuivre, entre à peu près 10 et 20% en poids de nickel et entre à peu près 4 et 12 % en poids de zinc entre à peu près 18 et 30% en poids de manganèse, une certaine teneur en bore et une certaine teneur en silicium.

27. Procédé selon la revendication 26, dans lequel le produit d'infiltration comprend à peu près 52,7% en poids de cuivre, à peu près 24% en poids de manganèse, à peu près 15% en poids de nickel, à peu près 8 % en poids de zinc, à peu près 0,15% en poids de bore et à peu près 0,15% en poids de silicium.

28. Elément composite de diamant, comprenant:

un support;

un composite de diamant fixé au support;

le composite de diamant comprenant une matrice comprenant une masse de grains agglomérés par un produit d'infiltration, la matrice étant formée par le procédé selon l'une quelconque des revendications 1 à 27.

Drawing