| (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 |
| (22) |
Date of filing: 22.08.2008 |
|
| (51) |
International Patent Classification (IPC):
|
|
| (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.

