Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
100 words
A method of coating a cutting tool body with an α-alumina coating consisting essentially of heating the cutting tool body while bringing the cutting tool body in contact with a hydrogen carrier gas to which has been added CO 2 , followed by CO, and than AlCl 3 so as to deposit an alpha-alumina layer on the cutting tool body, wherein the oxidation potential of the hydrogen carrier gas is controlled by maintaining a content of H 2 O in the carrier gas below 20 ppm of H 2 O prior to nucleation of said alpha-Al 2 O 3 .
Claim 2
Independent Claim
100 words
A method of coating a cutting tool body with an α-alumina coating consisting essentially of heating the cutting tool body while bringing the cutting tool body in contact with a hydrogen carrier gas to which has been added CO 2 , followed by CO, and than AlCl 3 so as to deposit an alpha-alumina layer on the cutting tool body, wherein the oxidation potential of the hydrogen carrier gas is controlled by maintaining a content of H 2 O in the carrier gas below 20 ppm of H 2 O prior to nucleation of said alpha-Al 2 O 3 .
Claim 3
Dependent Claim
47 words
The method of claim 1, wherein the H 2 O content of the hydrogen carrier gas is below 5 ppm of H 2 O prior to the nucleation of the alpha-Al 2 O 3 and the nucleation is carried out at a temperature of about 1000° C.
Claim 4
Dependent Claim
39 words
The method of claim 1, wherein the alpha-alumina layer has a thickness (d) of 0.5-25 μm and a single phase α-structure with a grain size (s): 0.5 μm<s<1 μm for 0.5μ<d<2.5 μm and 0.5 μm<s<3 μm for 2.5μ<d<25 μm.
Claim 5
Dependent Claim
28 words
The method of claim 1, wherein the surface roughness (R a ) of the alpha-alumina layer is less than 0.3 μm over a measured length of 0.25 mm.
Claim 6
Dependent Claim
65 words
The method of claim 1, wherein the alpha-alumina layer exhibits a texture coefficient TC greater than 1.3 for the (012) growth direction of the equivalent crystallographic planes defined as: ##EQU2## where I(hkl)=measured intensity of the (hkl) reflection o (hkl)=standard intensity of the ASTM standard powder pattern diffraction data n=number of reflections used in the calculation, (hkl) reflections used are: (012), (104), (110), (113), (024), (116).
Claim 7
Dependent Claim
15 words
The method of claim 5, wherein the texture coefficient TC (012) is greater than 1.5.
Claim 8
Dependent Claim
32 words
The method of claim 1, wherein the cutting tool body includes an intermediate layer of a metal carbide, metal nitride or metal carbonitride, the alpha-alumina layer being deposited on the intermediate layer.
Claim 9
Dependent Claim
25 words
The method of claim 1, wherein the cutting tool body includes an intermediate layer of TiCN, the alpha-alumina layer being deposited on the intermediate layer.