Abstract: A method for depositing a wear resistant composite ceramic coating on a cemented carbide or hard ceramic substrate. A gas mixture is passed over the substrate, including a halide vapor of Al, Zr, or Y and one or more oxidizing gases at about 900.degree.-1250.degree. C. for the cemented carbide or about 900.degree.-1500.degree. C. for the ceramic and between about 1 torr and about ambient pressure. During the deposition of the oxide, a different halide of Al, Zr, or Y is pulsed into the gas mixture. The parameters are controlled to deposit a fully dense, adherent, wear resistant, laminated oxide coating about 0.3-20 microns thick on the substrate having at least three layers each about 0.1-3 microns thick and each predominantly of a different material than that of the adjacent layers. Optionally, the process may be controlled to produce at least one layer in which discrete particles of the material predominantly in an adjacent layer are present in a matrix of the predominant material of the layer.

Abstract: A process for producing a wear resistant article, such as a cutting tool. Gaseous halides of two or more of aluminum, zirconium, and yttrium with other reactants are passed over a hard ceramic substrate at 900.degree.-1500.degree. C., and at 1 torr to about ambient pressure to form a composite ceramic coating on the substrate. The coating is a continuous first-phase metal oxide matrix having particles of at least one different metal oxide dispersed therein. In a preferred process, one or more of the metal halides is pulsed into the gaseous mixture containing a different metal halide, to control the deposition of the particles.

Abstract: A wear resistant article, such as a cutting tool. A hard ceramic or cemented carbide substrate is coated with a laminated oxide coating about 0.3-20 microns thick, having at least three ultrathin layers. Each layer is an oxide layer about 0.1-3 microns thick, predominantly of a different material than adjacent layers. The oxide or oxides of adjacent layers may be dispersed as discrete particles within one or more of the layers. A process for producing the article is also disclosed.

Abstract: A process for producing a wear resistant article, such as a cutting tool. Gaseous halides of two or more of aluminum, zirconium, and yttrium with other reactants are passed over a cemented carbide substrate at 900.degree.-1250.degree. C. and 1 torr to about ambient pressure to form a composite ceramic coating on the substrate. The coating is a continuous first-phase metal oxide matrix having particles of at least one different metal oxide dispersed therein. In a preferred process, one or more of the metal halides is pulsed into the gaseous mixture containing a different metal halide to control the deposition of the particles.