Titanium carbonitride coated stratified substrate and cutting inserts made from the same
First Claim
1. A titanium carbonitride coated cemented carbide article made according to a process comprising chemically vapor depositing a layer of titanium carbonitride directly on a cemented carbide substrate having a cobalt enriched surface 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 cemented carbide article having an eta phase in the substrate adjacent said titanium carbonitride coating, said eta phase comprising chemical compounds consisting essentially of cobalt, tungsten and carbon, and contacting said coated article with a carburizing gas for a sufficient time and at sufficient temperature to convert substantially all of said eta phase to elemental cobalt and tungsten carbide, said article having a normalized and regular coating/substrate interface and an interfacial region consisting essentially of carbon, titanium carbonitride and tungsten in a form unreacted with cobalt.
3 Assignments
0 Petitions
Accused Products
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.
-
Citations
22 Claims
- 1. A titanium carbonitride coated cemented carbide article made according to a process comprising chemically vapor depositing a layer of titanium carbonitride directly on a cemented carbide substrate having a cobalt enriched surface 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 cemented carbide article having an eta phase in the substrate adjacent said titanium carbonitride coating, said eta phase comprising chemical compounds consisting essentially of cobalt, tungsten and carbon, and contacting said coated article with a carburizing gas for a sufficient time and at sufficient temperature to convert substantially all of said eta phase to elemental cobalt and tungsten carbide, said article having a normalized and regular coating/substrate interface and an interfacial region consisting essentially of carbon, titanium carbonitride and tungsten in a form unreacted with cobalt.
- 8. A titanium carbonitride coated cemented carbide cutting tool made according to a process comprising chemically vapor depositing a layer of titanium carbonitride on a cemented carbide substrate, having matrix binder material comprising cobalt, 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 cemented carbide article having an eta phase in the substrate adjacent said titanium carbonitride coating, said eta phase comprising chemical compounds consisting essentially of cobalt, tungsten and carbon, and contacting said article with a carburizing gas for a sufficient time and at sufficient temperature to convert substantially all of said eta phase to elemental cobalt and tungsten carbide, said cutting tool having a uniform, fine grain, substantially porosity-free titanium carbonitride coating immediately adjacent said substrate, and an interfacial region having minimal cobalt and eta phase.
- 19. A wear resistant titanium carbonitride coated cemented carbide article comprising a cemented carbide substrate and at least one layer of titanium carbonitride coating, wherein said cemented carbide substrate comprises a cobalt enriched stratified surface and the layer of titanium carbonitride directly adjacent said substrate comprises an interfacial region consisting essentially of tungsten, titanium carbonitride and carbon whereby said coating is strongly bonded to the substrate.
-
21. A wear resistant titanium carbonitride coated cemented carbide article having a improved coating adherence comprising a cemented carbide substrate comprised of a hard refractory phase comprising tungsten carbide and a binder phase comprising cobalt, said substrate having a cobalt enriched surface, a layer of titanium carbonitride coating deposited directly upon said substrate, and a normalized and regular coating/substrate interface and an interfacial region proximate said interface being substantially free of eta phase.
-
22. A wear resistant titanium carbonitride coated cemented carbide article having a improved coating adherence comprising a cemented carbide substrate comprised of a hard refractory phase comprising tungsten carbide and a binder phase comprising cobalt, said substrate having a cobalt enriched surface, a layer of titanium carbonitride coating deposited directly upon said substrate, and an interfacial region therebetween consisting essentially of carbon, titanium carbonitride and tungsten, said coating having a solid solution interlayer of (W, Ti)C.
Specification