(19)
(11) EP 2 031 090 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
04.08.2010 Bulletin 2010/31

(43) Date of publication A2:
04.03.2009 Bulletin 2009/10

(21) Application number: 08014911.5

(22) Date of filing: 22.08.2008
(51) International Patent Classification (IPC): 
C23C 28/00(2006.01)
B23B 27/14(2006.01)
C23C 28/04(2006.01)
C23C 30/00(2006.01)
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR
Designated Extension States:
AL BA MK RS

(30) Priority: 31.08.2007 JP 2007225987

(71) Applicant: UNION TOOL CO.
Tokyo (JP)

(72) Inventors:
  • Ohori, Tetsutaro
    Shinagawa Tokyo (JP)
  • Sato, Akira
    Shinagawa Tokyo (JP)

(74) Representative: Kramer - Barske - Schmidtchen 
European Patent Attorneys Landsberger Strasse 300
80687 München
80687 München (DE)

   


(54) Hard covering film for cutting tool


(57) It is an object of the present invention to provide a hard covering film for a cutting tool which can improve the wear resistance beyond that of a conventional AlCrN film. According to the present invention, there is provided a hard covering film for a cutting tool formed on a cutting tool substrate, characterized in that: the hard covering film comprises a first multi-layer covering film layer formed by alternatingly layering two or more layers each of a first covering film layer and a second covering film layer; the first covering film layers have metal and semi-metal components that are expressed (in terms of at%) by Al(100-x-y-z)Cr(x)V(y)B(z) (where 20 ≤ x ≤ 40, 2 ≤ y ≤ 15, and 5 ≤ z ≤ 15), have N as a non-metallic element, and have unavoidable impurities; the second covering film layers have metal and semi-metal components that are expressed (in terms of at%) by Al(100-u-v-w)Cr(u)V(v)B(w) (where 20 ≤ u ≤ 40, 0 ≤ v ≤ 5, 0 ≤ w ≤ 5), have N as a non-metallic element, and have unavoidable impurities; the relationship between y and v such that y ≥ v is satisfied; and the relationship between z and w such that z - 5 ≥ w is satisfied.





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