USRE44870EExpiredUtility
Aluminum oxide coated cutting tool and method of manufacturing thereof
Est. expiryJan 14, 2014(expired)· nominal 20-yr term from priority
Inventors:Bjorn Ljungberg
Y10T407/27C23C 16/0272C23C 16/403C23C 30/005
44
PatentIndex Score
0
Cited by
113
References
30
Claims
Abstract
A body such as a cutting tool coated with refractory single- or multilayers, wherein specific layers are characterized by a controlled microstructure and phase composition with crystal planes preferably grown in a preferential direction with respect to the surface of the coated body. The coating includes one or several refractory layers of which at least one layer is a dense, fine-grained layer of α-Al 2 O 3 preferably textured in the (104) direction. The coated tool exhibits excellent surface finish and shows much improved wear and toughness properties compared to prior art objects when used for machining steel, cast iron and, particularly, when machining nodular cast iron. REEXAMINATION RESULTS The questions raised in reexamination proceedings Nos. 90/009,410 and 90/009,666, filed May 5, 2009 and Feb. 24, 2010 respectively, have been considered, and the results thereof are reflected in this reissue patent which constitutes the reexamination certificate required by 35 U.S.C. 307 as provided in 37 CFR 1.570(e) for ex parte reexaminations, and/or the reexamination certificate required by 35 U.S.C. 316 as provided in 37 CFR 1.997(e) for inter partes reexaminations.
Claims
exact text as granted — not AI-modifiedWhat is claimed is:
1. A body at least partially coated with one or more refractory layers of which at least one layer is alumina, said alumina layer having a thickness d of 0.5 μm≦d≦25 μm with a grain size (s) of
0.5 μm<s<4 μm;
said alumina layer consisting of single phase α-structure textured in the (104)-direction with a texture coefficient larger than 1.5 2.5, the texture coefficient (TC) being defined by calculation:
TC
(
hkl
)
=
I
(
hkl
)
I
0
(
hkl
)
{
1
n
∑
I
(
hkl
)
I
0
(
hkl
)
}
-
1
where
I(hkl)=measured intensity of the (hkl) reflection
I o (hkl)=standard intensity of the ASTM standard powder pattern diffraction data
n=number of reflections used in the calculation and (hkl) reflections used are: (012), (104), (110), (113), (024), (116),
said alumina layer being an exposed outermost layer in contact with a TiC x N y O z -layer.
2. A body according to claim 1 , wherein said TiC x N y O z -layer is an innermost layer of the coating.
3. A body according to claim 1 , wherein said body is a cutting tool insert of cemented carbide, titanium based carbonitride or other ceramics.
4. A body according to claim 1 , wherein the texture coefficient is larger than 2.5.
5. A body according to claim 1 , wherein the texture coefficient is larger than 3.0.
6. A body according to claim 1 , wherein the alumina layer has a fine-grained microstructure of alumina grains with 80% or more of the alumina grains having a grain size of ±50% of an average grain size of the alumina layer.
7. A body according to claim 1 , wherein the alumina layer has a thickness of 4 to 8 μm and an average grain size of 1 to 3 μm.
8. The coated body of claim 1 , wherein the alumina layer has been deposited by a chemical vapor deposition process wherein H 2 S dopant is added to reactant gases during the deposition process.
9. The coated body of claim 1 , wherein the alumina layer has been deposited during a chemical vapor deposition process wherein a sulfur dopant is added to reactant gases during the deposition process.
10. The coated body of claim 1 , wherein the alumina layer has a surface roughness (R a ) of less than 0.3 μm over a measured length of 0.25 mm.
11. The coated body of claim 1 , wherein the alumina layer has been smoothened by wet blasting.
12. The coated body of claim 1 , wherein 0.5 μm<d<2.5 μm and the grain size is greater than 0.5 μm and less than 1 μm.
13. The coated body of claim 1 , wherein 2.5 μm<d<25 μm and the grain size is greater than 0.5 μm and less than 4 μm.
14. The coated body of claim 1, wherein the texture coefficient is larger than 3.0 and the alumina layer has a fine-grained microstructure of alumina with 80% or more of the alumina grains having a grain size of ±50% of an average grain size of the alumina layer.
15. The coated body of claim 1, wherein the texture coefficient is larger than 3.0 and the alumina layer has a thickness d of 0.5 μm≦d≦2.5 μm and the grain size is greater than 0.5 μm and less than 1 μm.
16. The coated body of claim 1, wherein the texture coefficient is larger than 3.0 and the alumina layer has a thickness d of 2.5 μm<d<25 μm and the grain size is greater than 0.5 μm and less than 4 μm.
17. The coated body of claim 16, wherein said body is a cutting tool insert of cemented carbide, titanium based carbonitride or other ceramics.
18. A body at least partially coated with one or more refractory layers of which at least one layer is alumina, said alumina layer having a thickness 4 to 8 μm with an average grain size of 1 to 3 μm,
said alumina layer consisting of single phase α-structure textured in the (104)-direction with a texture coefficient larger than 3.0, the texture coefficient (TC) being defined by calculation:
TC
(
hkl
)
=
I
(
hkl
)
I
0
(
hkl
)
{
1
n
∑
I
(
hkl
)
I
0
(
hkl
)
}
-
1
where
I(hkl)=measured intensity of the (hkl) reflection
I o (hkl)=standard intensity of the ASTM standard powder pattern diffraction data
n=number of reflections used in the calculation and (hkl) reflections used are: (012), (104), (110), (113), (024), (116),
wherein the alumina layer is an exposed outermost layer in contact with an inner TiC x N y O z -layer.
19. The coated body claim 18, wherein the alumina layer has been smoothened by wet blasting.
20. The coated body of claim 18, wherein the alumina layer has a fine-grained microstructure of alumina grains with 80% or more of the alumina grains having a grain size of ±50% of the average grain size of the alumina layer.
21. A body at least partially coated with one or more refractory layers of which at least one layer is alumina, said alumina layer having a thickness d of 0.5 μm≦d≦25 μm with a grain size (s) of
0.5 μm<s<4 μm;
said alumina layer consisting of single phase α-structure textured in the (104)-direction with a texture coefficient larger than 3.0, the texture coefficient (TC) being defined by calculation:
TC
(
hkl
)
=
I
(
hkl
)
I
0
(
hkl
)
{
1
n
∑
I
(
hkl
)
I
0
(
hkl
)
}
-
1
where
I(hkl)=measured intensity of the (hkl) reflection
I o (hkl)=standard intensity of the ASTM standard powder pattern diffraction data
n=number of reflections used in the calculation and (hkl) reflections used are: (012), (104), (110), (113), (024), (116),
said alumina layer being an exposed outermost layer in contact with an innermost TiC x N y O z -layer, and
wherein the alumina layer has a fine-grained microstructure of alumina grains with 80% or more of the alumina grains having a grain size of ±50% of an average grain size of the alumina layer.
22. The coated body of claim 21, wherein the alumina layer has been smoothened by wet blasting.
23. A body at least partially coated with one or more refractory layers of which at least one layer is alumina, said alumina layer having a thickness d of 0.5 μm≦d≦25 μm with a grain size (s) of
0.5 μm<s<4 μm;
said alumina layer consisting of single phase α-structure textured in the (104)-direction with a texture coefficient larger than 3.0, the texture coefficient (TC) being defined by calculation:
TC
(
hkl
)
=
I
(
hkl
)
I
0
(
hkl
)
{
1
n
∑
I
(
hkl
)
I
0
(
hkl
)
}
-
1
where
I(hkl)=measured intensity of the (hkl) reflection
I o (hkl)=standard intensity of the ASTM standard powder pattern diffraction data
n=number of reflections used in the calculation and (hkl) reflections used are: (012), (104), (110), (113), (024), (116),
said alumina layer being an exposed outermost layer in contact with a TiC x N y O z -layer,
wherein the alumina layer has been deposited by a chemical vapor deposition process wherein H 2 S dopant is added to reactant gases during the deposition process.
24. The coated body of claim 23, wherein the TiC x N y O z -layer is an innermost layer.
25. The body according to claim 23, wherein said body is a cutting tool insert of cemented carbide, titanium based carbonitride or other ceramics.
26. The coated body of claim 23, wherein the texture coefficient is larger than 3.0 and the alumina layer has a fine-grained microstructure of alumina with 80% or more of the alumina grains having a grain size of ±50% of an average grain size of the alumina layer.
27. The coated body of claim 23, wherein the texture coefficient is larger than 3.0 and the alumina layer has a thickness d of 0.5 μm<d<2.5 μm and the grain size is greater than 0.5 μm and less than 1 μm.
28. The coated body of claim 23, wherein the texture coefficient is larger than 3.0 and the alumina layer has thickness d of 2.5 μm<d<25 μm and the grain size is an 0.5 μm and less than 4 μm.
29. The coated body of claim 23, wherein the alumina layer has been smoothened by wet blasting.
30. The coated body of claim 23, wherein the thickness of the alumina layer is 4 to 8 μm and an average grain size is 1 to 3 μm.Cited by (0)
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