US5665431A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Titanium carbonitride coated stratified substrate and cutting inserts made from the same
Assignee: Valenite LLC
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Filing: 1991-09-03
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Granted: 1997-09-09
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Expires: 2011-09-03
Abstract
Abstract A process for forming a titanium carbonitride coated stratified cobalt enriched cemented carbide cutting insert, said cemented carbide is comprised of more than 70 percent by weight tungsten carbide and has a matrix binder comprising cobalt with a cobalt enriched stratified surface. The process comprises chemically vapor depositing a layer of titanium carbonitride on said cemented carbide substrate by heating gaseous reactants comprising titanium chloride, methane, hydrogen, and nitrogen with an optimum methane/nitrogen ratio, under suitable conditions to form a titanium carbonitride coated insert having an eta phase in the cemented carbide substrate adjacent said titanium carbonitride coating. The eta phase comprises chemical compounds consisting essentially of cobalt, tungsten and carbon, and the titanium carbonitride surface is contacted with a carburizing gas for a sufficient time and at a sufficient temperature to convert substantially all of said eta phase to elemental cobalt and tungsten carbide.
Inventors
- 👤 Krishnan Narasimhan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:28
CPC Classifications
C; C23; C23C; C23C16/00; C23C16/44; C23C16/455; C23C16/45512; C23C16/22; C23C16/30; C23C16/36; C23C16/56; C23C30/00; C23C30/005; C23C8/00; C23C8/02; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31678
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
143 words
A process for forming a titanium carbonitride coated stratified cobalt enriched cemented carbide cutting insert, said cemented carbide comprising about 70 to 97 percent by weight tungsten carbide and a matrix binder comprising cobalt with a cobalt enriched stratified surface, wherein said process comprises chemically vapor depositing a layer of titanium carbonitride on said cemented carbide substrate by heating gaseous reactants comprising titanium chloride, methane, hydrogen, and nitrogen with an optimum carbon/nitrogen ratio, under suitable conditions to form a titanium carbonitride coated insert having an eta phase in the cemented carbide substrate adjacent said titanium carbonitride coating, said eta phase comprising chemical compounds consisting essentially of cobalt, tungsten and carbon, and contacting said titanium carbonitride surface with a carburizing gas for a sufficient time and at a sufficient temperature to convert substantially all of said eta phase to elemental cobalt and tungsten carbide.
Claim 2
Dependent Claim
143 words
A process for forming a titanium carbonitride coated stratified cobalt enriched cemented carbide cutting insert, said cemented carbide comprising about 70 to 97 percent by weight tungsten carbide and a matrix binder comprising cobalt with a cobalt enriched stratified surface, wherein said process comprises chemically vapor depositing a layer of titanium carbonitride on said cemented carbide substrate by heating gaseous reactants comprising titanium chloride, methane, hydrogen, and nitrogen with an optimum carbon/nitrogen ratio, under suitable conditions to form a titanium carbonitride coated insert having an eta phase in the cemented carbide substrate adjacent said titanium carbonitride coating, said eta phase comprising chemical compounds consisting essentially of cobalt, tungsten and carbon, and contacting said titanium carbonitride surface with a carburizing gas for a sufficient time and at a sufficient temperature to convert substantially all of said eta phase to elemental cobalt and tungsten carbide.
Claim 3
Dependent Claim
31 words
The process for forming a coated cemented carbide cutting insert according to claim 1 wherein the thickness of said titanium carbonitride coating is from about 2 microns to about 8 microns.
Claim 4
Dependent Claim
28 words
The process for forming a coated cemented carbide cutting insert according to claim 2 wherein said deposition reaction proceeds according to the following formula: TiCl.sub.4 +CH.sub.4 +1/2N.sub.2 →TiCN+4HCl.
Claim 5
Dependent Claim
55 words
The process for forming a titanium carbonitride coated stratified cobalt substrate according to claim 3, wherein the carbon/nitrogen ratio, TiC x N y , is controlled for optimum wear resistance in the TiCN layer, and wherein x is a number from about 0.3 to 0.6, and y is a number from about 0.7 to 0.4.
Claim 6
Dependent Claim
57 words
The process for forming a titanium carbonitride coated stratified cobalt substrate according to claim 4, wherein the said nitrogen partial pressure in the gas phase distributes the cubic carbides at the coating/substrate interface in an enhanced distribution mode, and presents a uniform interface for nucleation and growth of TiCN layer, thereby promoting adhesion and uniformity of coating.
Claim 7
Dependent Claim
38 words
The process for forming a titanium carbonitride coated stratified cobalt substrate according to claim 5, wherein the C/N ratio in the deposited layer by a carbon correction cycle is controlled to enhance the wear resistance of coated layer.
Claim 8
Dependent Claim
34 words
The process for forming a coated cemented carbide cutting insert according to claim 6, wherein said carburizing gas comprises a component having the formula CH 2 n+2 wherein n is from 1 to 4.
Claim 9
Dependent Claim
48 words
The process for forming a titanium carbonitride coated stratified cobalt substrate according to claim 7, wherein the concentration of said carburizing gas is maintained at a concentration of about 0.6 to about 0.8 percent by volume to permit sufficient carbon to be available to diffuse through said coating.
Claim 10
Dependent Claim
27 words
A process for forming a titanium carbonitride stratified cobalt substrate according to claim 8, wherein said carburizing gas includes an inert component, said inert component comprising hydrogen.
Claim 11
Dependent Claim
20 words
A process for forming a titanium carbonitride stratified cobalt substrate according to claim 9, wherein said carburizing gas is methane.
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