Abstract: Method for removing a portion of the binder phase from the surface of a substrate that is composed of particles of at least a first phase joined together by the binder phase, and wherein the surface is etched by contacting it with a gas flow of an etchant gas and a second gas. The second gas is one or more gases that will not react with the substrate or the removed binder phase and will not alter the oxidation state of the substrate during etching.

Abstract: Methods of coating cutting tool inserts including a hard substrate and a plurality of coatings are disclosed. In one embodiment, the method comprises applying a first coating of at least 2 microns to at least a portion of the hard substrate and applying a second coating. The first coating can comprise at least one of a metal carbide, a metal nitride, and a metal carbonitride of at least one metal selected from zirconium and hafnium. The second coating can comprise at least one of a metal carbide, a metal boride, a metal nitride, and a metal oxide of a metal selected from groups IIIA, IVB, VB, and VIB of the periodic table. Optionally, third and fourth coatings are also applied to the cutting tool inserts.

Abstract: A cutting tool insert comprises a hard metal substrate having at least two wear-resistant coatings including an exterior ceramic coating and a coating under the ceramic coating being a metal carbonitride having a nitrogen to carbon atomic ratio between 0.7 and 0.95 which causes the metal carbonitride to form projections into the ceramic coating improving adherence and crater resistance of the ceramic coating. Also disclosed is a cutting tool insert including a hard substrate and at least first and second coatings on at least a portion of said substrate. The first coating is of at least about 2 microns, is in contact with the substrate, and includes at least one of a metal carbide, a metal nitride, and a metal carbonitride of a metal selected from the group consisting of zirconium and hafnium. The second coating may include at least one of a metal carbide, a metal nitride, and a metal oxide of a metal selected from groups IIIA, IVB, VB, and VIB of the periodic table.

Abstract: A cutting tool insert comprises a hard metal substrate having at least two wear-resistant coatings including an exterior ceramic coating and a coating under the ceramic coating being a metal carbonitride having a nitrogen to carbon atomic ratio between 0.7 and 0.95 which causes the metal carbonitride to form projections into the ceramic coating improving adherence and crater resistance of the ceramic coating. Also disclosed is a cutting tool insert including a hard substrate and at least first and second coatings on at least a portion of said substrate. The first coating is of at least about 2 microns, is in contact with the substrate, and includes at least one of a metal carbide, a metal nitride, and a metal carbonitride of a metal selected from the group consisting of zirconium and hafnium. The second coating may include at least one of a metal carbide, a metal nitride, and a metal oxide of a metal selected from groups IIIA, IVB, VB, and VIB of the periodic table.

Abstract: Method for removing a portion of the binder phase from the surface of a substrate that is composed of particles of at least a first phase joined together by the binder phase, and wherein the surface is etched by contacting it with a gas flow of an etchant gas and a second gas. The second gas is one or more gases that will not react with the substrate or the removed binder phase and will not alter the oxidation state of the substrate during etching.

Abstract: Method for removing a portion of the binder phase from the surface of a substrate that is composed of particles of at least a first phase joined together by the binder phase, and wherein the surface is etched by contacting it with a gas flow of an etchant gas and a second gas. The second gas is one or more gases that will not react with the substrate or the removed binder phase and will not alter the oxidation state of the substrate during etching.

Abstract: A cutting tool insert comprises a hard metal substrate having at least two wear-resistant coatings including an exterior ceramic coating and a coating under the ceramic coating being a metal carbonitride having a nitrogen to carbon atomic ratio between 0.7 and 0.95 which causes the metal carbonitride to form projections into the ceramic coating improving adherence and fatigue strength of the ceramic coating.

Abstract: A cutting tool insert comprises a hard metal substrate having at least two wear-resistant coatings including an exterior ceramic coating and a coating under the ceramic coating being a metal carbonitride having a nitrogen to carbon-plus-nitrogen atomic ratio between 0.7 and 0.95 which causes the metal carbonitride to form projections into the ceramic coating improving adherence and fatigue strength of the ceramic coating.