Coated cutting tool insert for turning of steels
AssigneeSeco Tools AB
InventorHindrik Engstrom
Life of this patent
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Abstract
A cutting tool insert for turning of hardened steels and tool steels includes a textured CVD α-Al2O3 coated cemented carbide body. The cemented carbide body has 4.0-7.0 wt-% Co and 0.25-0.50 wt-% Cr and an S-value of 0.68-0.88 and a coercivity (Hc) of 28-38 kA/m. The α-Al2O3 layer has a thickness ranging from 7 to 12 μm, is composed of columnar grains having a length/width ratio from 2 to 12 and is deposited on an MTCVD Ti(C,N) layer having a thickness from 4 to 12 μm. The alumina layer is characterised by a pronounced (006) growth texture.
Claims21
A cutting tool insert, comprising:
- a cemented carbide body that comprises WC, 4.0-7.0 wt-% Co, 0.25-0.50 wt-% Cr, having an S-value of 0.68-0.88, and a coercivity, Hc, of 28-38 kA/m;
- and adjacent
- a coating between 11 and 24 μm thick deposited by CVD wherein at least the uppermost layer is a 7-12 μm thick α-Al2O3 alumina layer textured in the <006>-direction with a texture coefficient TC(006) >2, TC(012), TC(110), TC(113), TC(202), TC(024) and TC(116) all <1, and TC(104) being a second highest texture coefficient, the texture coefficient TC(hkl) being defined by:
- TC
-
- (
- hkl
- )
- =
- I
-
- (
- hkl
- )
- I
- 0
-
- (
- hkl
- )
-
- [
- 1
- n
-
- ∑
- n
- =
- 1
- n
-
- I
-
- (
- hkl
- )
- I
- 0
-
- (
- hkl
- )
- ]
- -
- 1
- where
- I(hkl)=measured intensity of the (hkl) reflection,
- I0(hkl)=standard intensity according to JCPDS card no. 46-1212,
- n=number of reflections used in the calculation (8),
- (hkl) reflections used are:
- (012), (104), (110), (006), (113), (202), (024) and (116).
A cutting tool insert, comprising:
- a cemented carbide body that comprises WC, 4.0-7.0 wt-% Co 0.30-0.45 wt-% Cr, having an S-value of 0.7-0.8, and a coercivity, Hc, of 30-34 kA/m;
- a first layer on the cemented carbide substrate having a thickness of 5-10 μm of MTCVD Ti(C,N) being composed of columnar grains;
- and
- a second layer between 11 and 24 μm thick deposited by CVD wherein the second layer is a 8-11 μm thick α-Al2O3 alumina layer composed of columnar grains having a length/width ratio of 4-8, the alumina layer being textured in the <006>-direction with a texture coefficient TC(006) >4 and <8, TC(012), TC(110), TC(113), TC(202), TC(024) and TC(116) all <1, and TC(104) being a second highest texture coefficient, the texture coefficient TC(hkl) being defined by:
- TC
-
- (
- hkl
- )
- =
- I
-
- (
- hkl
- )
- I
- 0
-
- (
- hkl
- )
-
- [
- 1
- n
-
- ∑
- n
- =
- 1
- n
-
- I
-
- (
- hkl
- )
- I
- 0
-
- (
- hkl
- )
- ]
- -
- 1
- where
- I(hkl)=measured intensity of the (hkl) reflection,
- I0(hkl)=standard intensity according to JCPDS card no. 46-1212,
- n=number of reflections used in calculation (8),
- (hkl) reflections used are:
- (012), (104), (110), (006), (113), (202), (024) and (116).
A cutting tool insert, comprising:
- a cemented carbide body that comprises WC, 4.0 to less than 6 wt-% Co, 0.25-0.50 wt-% Cr, having an S-value of 0.68-0.88, and a coercivity, Hc, of 28-38 kA/m;
- and adjacent
- a coating between 11 and 24 μm thick deposited by CVD wherein at least the uppermost layer is a 7-12 μm thick α-Al2O3 alumina layer textured in the <006>-direction with a texture coefficient TC(006) >2, TC(012), TC(110), TC(113), TC(202), TC(024) and TC(116) all <1, and TC(104) being a second highest texture coefficient, the texture coefficient TC(hkl) being defined by:
- TC
-
- (
- hkl
- )
- =
- I
-
- (
- hkl
- )
- I
- 0
-
- (
- hkl
- )
-
- [
- 1
- n
-
- ∑
- n
- =
- 1
- n
-
- I
-
- (
- hkl
- )
- I
- 0
-
- (
- hkl
- )
- ]
- -
- 1
- where
- I(hkl)=measured intensity of the (hkl) reflection,
- I0(hkl)=standard intensity according to JCPDS card no. 46-1212,
- n=number of reflections used in the calculation (8),
- (hkl) reflections used are:
- (012), (104), (110), (006), (113), (202), (024) and (116).
Dependencies are inferred from the claim text.