Coated cutting insert for rough turning
A cutting tool insert with a cemented carbide and a coating. The cemented carbide substrate includes WC, 7 to 12 wt-% Co, 5 to 11 wt-% cubic carbides of metals from the groups IVb, Vb and VIb with a binder phase that is highly alloyed with cobalt. The tungsten carbide phase has a mean intercept length of 0.7 to 1.4 μm. The coating includes at least one 2 to 12 μm thick α-Al 2 O 3 layer composed of columnar grains with texture coefficients: TC(012)>2.2 and TC(024)>0.6×TC(012).
1. A cutting tool insert comprising:
a cemented carbide substrate; and
a coating,
wherein the cemented carbide substrate comprises WC, 7 to 12 wt-% Co and 5 to 11 wt-% of cubic carbides of metals from groups IVb, Vb and VIb of the periodic table, a Co-binder that is highly alloyed with W and has an S-value of 0.79 to 0.89, a tungsten carbide phase having a mean intercept length of 0.7 to 1.4 μm,
wherein the coating comprises at least one 2 to 12 μm alumina layer including columnar α-Al 2 O 3 grains and a texture coefficient TC(hkl) of (hkl) reflections (012), (104), (110), (113), (024), (116),
wherein TC(012)>2.2 and TC(024)>0.6×TC(012), and
wherein texture coefficient TC(hkl) is defined as
TC
(
hkl
)
=
I
(
hkl
)
I
0
(
hkl
)
[
1
n
∑
I
(
hkl
)
I
0
(
hkl
)
]
-
1
where
I(hkl)=measured intensity of (hkl) reflection
I 0 (hkl)=standard intensity according to JCPDS card no 46-1212
n=number of reflections used in calculation.
2. The cutting tool insert according to claim 1 , wherein the columnar α-Al 2 O 3 grains have a length/width ratio from 2 to 10.
3. The cutting tool insert according to claim 2 , wherein the length/width ratio is 4 to 8.
4. The cutting tool insert according to claim 1 , comprising a first layer adjacent the cemented carbide substrate including CVD Ti(C,N), CVD TiN, CVD TiC, MTCVD Ti(C,N), MTCVD Zr(C,N), MTCVD Ti(B,C,N), CVD HfN or combinations thereof, the first layer having a thickness of from 1 to 10 μm.
5. The cutting tool insert according to claim 4 , wherein the thickness of the first layer is 3 to 8 μm.
6. The cutting tool insert according to claim 5 , wherein the thickness of the first layer is about 6 μm.
7. The cutting tool insert according to claim 4 , wherein the first layer includes MTCVD Ti(C,N).
8. The cutting tool insert according to claim 1 , wherein a total thickness of the coating is 7 to 15 μm.
9. The cutting tool insert according to claim 8 , wherein the total thickness of the coating is 8 to 13 μm.
10. The cutting tool insert according to claim 4 , wherein the coating comprises a modified bonding layer including an Al concentration gradient positioned between the first layer and the alumina layer.
11. The cutting tool insert according to claim 1 , wherein the mean intercept length of the tungsten carbide phase is 0.9 to 1.3 μm.
12. The cutting tool insert according to claim 1 , wherein the cemented carbide substrate includes a binder phase enriched and an essentially cubic carbide free surface zone of a thickness of 10 to 40 μm.
13. The cutting tool insert according to claim 1 , wherein TC(012) is 2.5 to 3.5.
14. The cutting tool insert according to claim 1 , wherein TC(104), TC(110), TC(113), TC(116) are each less than 0.4.
15. The cutting tool insert according to claim 1 , wherein TC(104), TC(110), TC(113), TC(116) are each less than 0.3.
16. A cutting tool insert comprising:
a cemented carbide substrate; and
a coating,
wherein the cemented carbide substrate consists essentially of WC, 7 to 12 wt-% Co and 5 to 11 wt-% of cubic carbides of metals from groups IVb, Vb and VIb of the periodic table, a Co-binder that is highly alloyed with W and has an S-value of 0.79 to 0.89, a tungsten carbide phase having a mean intercept length of 0.7 to 1.4 μm,
wherein the coating consists essentially of at least one 2 to 12 μm alumina layer including columnar α-Al 2 O 3 grains and a texture coefficient TC(hkl) of (hkl) reflections (012), (104), (110), (113), (024), (116),
wherein TC(012)>2.2 and TC(024)>0.6×TC(012), and
wherein texture coefficient TC(hkl) is defined as
TC
(
hkl
)
=
I
(
hkl
)
I
0
(
hkl
)
[
1
n
∑
I
(
hkl
)
I
0
(
hkl
)
]
-
1
where
I(hkl)=measured intensity of (hkl) reflection
I 0 (hkl)=standard intensity according to JCPDS card no 46-1212
n=number of reflections used in calculation.
17. The cutting tool insert according to claim 16 , wherein TC(012) is 2.5 to 3.5.
18. The cutting tool insert according to claim 16 , wherein TC(104), TC(110), TC(113), TC(116) are each less than 0.4.
19. The cutting tool insert according to claim 16 , wherein TC(104), TC(110), TC(113), TC(116) are each less than 0.3.
20. A cutting tool insert comprising:
a cemented carbide substrate; and
a coating,
wherein the cemented carbide substrate comprises WC, 7 to 12 wt-% Co and 5 to 11 wt-% of cubic carbides of metals from groups IVb, Vb and VIb of the periodic table, a Co-binder that is highly alloyed with W and has an S-value of 0.79 to 0.89, a tungsten carbide phase having a mean intercept length of 0.7 to 1.4 μm and wherein the cemented carbide substrate includes a binder phase enriched and an essentially cubic carbide free surface zone of a thickness of 10 to 40 μm,
wherein the coating comprises at least one 2 to 12 μm alumina layer including columnar α-Al 2 O 3 grains having a length to width ratio from 2 to 10 and a texture coefficient TC(hkl) of (hkl) reflections (012), (104), (110), (113), (024), (116),
wherein TC(012)>2.2 and TC(024)>0.6×TC(012), and
wherein texture coefficient TC(hkl) is defined as
TC
(
hkl
)
=
I
(
hkl
)
I
0
(
hkl
)
[
1
n
∑
I
(
hkl
)
I
0
(
hkl
)
]
-
1
where
I(hkl)=measured intensity of (hkl) reflection
I 0 (hkl)=standard intensity according to JCPDS card no 46-1212
n=number of reflections used in calculation, and
wherein the coating further comprises a first layer adjacent the cemented carbide substrate including CVD Ti(C,N), CVD TiN, CVD TiC, MTCVD Ti(C,N), MTCVD Zr(C,N), MTCVD Ti(B,C,N), CVD HfN or combinations thereof, the first layer having a thickness of from 1 to 10 μm.
21. The cutting tool insert according to claim 20 , wherein the thickness of the first layer is about 3 to 8 μm, the first layer is MTCVD Ti(C,N), and a total thickness of the coating is 7 to 15 μm.
22. The cutting tool insert according to claim 20 , wherein TC(012) is 2.5 to 3.5.
23. The cutting tool insert according to claim 20 , wherein TC(104), TC(110), TC(113), TC(116) are each less than 0.4.
24. The cutting tool insert according to claim 20 , wherein TC(104), TC(110), TC(113), TC(116) are each less than 0.3.
25. The cutting tool insert according to claim 20 , wherein the coating comprises a modified bonding layer including an Al concentration gradient, the modified bonding layer positioned between the first layer and the alumina layer.
26. The cutting tool insert according to claim 20 , wherein TC(012) is 2.5 to 3.5 and TC(104), TC(110), TC(113), TC(116) are each less than 0.4.