Oxide bond for aluminum oxide coated cutting tools

Claim 2

In a process of manufacturing a hard metal cutting tool insert, the improvement comprising: (a) coating the insert with a thin layer of a carbide, nitride, or carbonitride of a refractory metal; (b) subjecting the thin layer to an oxidizing atmosphere to provide an oxide of said refractory metal of a higher order than a monoxide; (c) reducing the higher oxide layer to provide a monoxide on the surface thereof; and (d) depositing a hard water resistant coating on the said monoxide surface.

Claim 3

The invention as recited in claim 1 wherein the hard metal is a cemented carbide and the monoxide surface is directly adjacent thereto.

Claim 4

The process as recited in claim 2 wherein said refractory metal is at least one of the metals taken from the class consisting of Titanium, Hafnium, Vanadium and Zirconium.

Claim 5

The invention as recited in claim 3 wherein said reducing step comprises treatment of said higher oxide with a gas mixture of H 2 and at least one of TiCl 4 , HfCl 4 , ZrCl 4 .

Claim 6

The process of claim 4 wherein said refractory metal is titanium.

Claim 7

The invention as recited in claim 5 wherein the said higher oxide includes one or more of TiO 2 , Ti 2 O 3 , Ti 3 O 5 , and said hard wear resistant coating is a ceramic.

Claim 8

The invention as recited in claim 6 wherein said reducing step comprises treatment of said higher oxide with a gas mixture of H 2 and TiCl 4 .

Claim 9

The invention as recited in claim 7 wherein said ceramic is Al 2 O 3 .

Claim 10

In a process of manufacturing a cemented carbide cutting insert, the improvement comprising: (a) depositing a thin layer of TiC on said insert by chemical vapor deposition of TiC from a gas mixture of H 2 , TiCl 4 , and CH 4 ; (b) subjecting said thin TiC layer to an oxidizing atmosphere at elevated temperature to convert TiC to a layer of a higher oxide than TiO; (c) subjecting said higher oxide layer to a reducing atmosphere of a mixture of H 2 and TiCl 4 at elevated temperature to provide a TiO layer; and (d) depositing a thin hard wear resistant ceramic coating on said TiO layer by vapor deposition at elevated temperatures from a gas mixture of a metal halide, H 2 and H 2 O.

Claim 11

In a process of manufacturing a cemented carbide cutting insert, the improvement comprising: (a) depositing a thin layer of TiC on said insert by chemical vapor deposition of TiC from a gas mixture of H 2 , TiCl 4 , and CH 4 ; (b) subjecting said thin TiC layer to an oxidizing atmosphere at elevated temperature to convert TiC to a layer of a higher oxide than TiO; (c) subjecting said higher oxide layer to a reducing atmosphere of a mixture of H 2 and TiCl 4 at elevated temperature to provide a TiO layer; and (d) depositing a thin hard wear resistant ceramic coating on said TiO layer by vapor deposition at elevated temperatures from a gas mixture of a metal halide, H 2 and H 2 O.

Claim 12

The invention as recited in claim 9 wherein said ceramic is Al 2 O 3 and said halide is aluminum trichloride AlCl 3 .

Claim 13

A product produced by the process of claim 10.

Claim 14

A cemented tungsten carbide cutter insert having multiple layers thereon, comprising the combination of a thin hard wear resistant outermost layer of Al 2 O 3 securely bonded to a multilayered inner layer of TiO which was converted from one or more higher oxides of titanium which one or more higher oxides were converted from a TiC layer adjacent the cemented carbide.

Claim 15

A cemented tungsten carbide cutter insert having multiple layers thereon, comprising the combination of a thin hard wear resistant outermost layer of Al 2 O 3 securely bonded to a multilayered inner layer of TiO which was converted from one or more higher oxides of titanium which one or more higher oxides were converted from a TiC layer adjacent the cemented carbide.