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.

Abstract: A wear resistant article, such as a cutting tool. A hard ceramic substrate is coated with a composite ceramic coating having at least two phases. The first phase is a continuous oxide matrix layer 0.1-20 microns thick of oxides of alumina, zirconia, or yttria. At least one discontinuous second or additional phase of oxides of aluminum, zirconium, or yttrium, or solid solutions thereof, is dispersed as discrete particles within the matrix layer. The additional phase material is different from the matrix material.

Abstract: A wear resistant article, such as a cutting tool. A cemented carbide substrate is coated with a composite ceramic coating having at least two phases. The first phase is a continuous oxide matrix layer 0.1-20 microns thick of oxides of alumina, zirconia, or yttria. At least one discontinuous second or additional phase of oxides of aluminum, zirconium, or yttrium, or solid solutions thereof, is dispersed as discrete particles within the matrix layer. The additional phase material is different from the matrix material.

Abstract: A hot chamber die casting apparatus for casting aluminum, zinc, magnesium, copper and their alloys as well as other metals which, in the molten state, corrode ferrous materials. The apparatus comprises a crucible, an injection pump in the crucible, and a gooseneck leading from the crucible to an outlet nozzle. The parts of the apparatus have coatings or sleeves of materials which resist corrosion, abrasion, erosion and mechanical or thermal shocks.

Abstract: A corrosion-resistant surface formed of a sulfide-forming metal, in particular nickel, is first subjected to an electric plasma in an atmosphere containing hydrogen sulfide to form an adherent sulfide on said surface. The sulfided surface is then exposed to simultaneous cathodic sputtering of at least one solid lubricant which is a chalcogen compound of layer structure, in particular MoS.sub.2, and at least one hydrophobic solid polymer, in particular PTFE. The coating thus formed is a composite coating in which the particles of the chalcogen compound are coated by the polymer. When the surface of the part to be coated does not consist of a corrosion-resistant sulfide-forming metal, a layer of such a metal is first deposited by cathodic sputtering. The composite coating withstands a wet oxidizing atmosphere, contrary to a coating of MoS.sub.2 alone, and the method is applicable to any mechanical part intended to rub on other surfaces, such as a watch balance wheel staff and ball or roller bearings.

Abstract: A diffusion barrier and separation substance for metal parts which adjoin each other in an oxygen-free, inert and preferably a helium-containing atmosphere such as used in a closed-cycle high temperature reactor or gas turbine comprises first and second adjoining metal parts with a hexagonal boron nitride placed between said parts. The hexagonal boron nitride is applied to the boundary surface of the metal parts in an aqueous or organic suspension prepared as a pasty, putty-like or brushable liquid substance. The substance contains from 5 to 50% of boron nitride, from 0.5 to 30% of binders and from 2 to 6% of swelling agents and 50 to 90% liquid suspension medium. The suspension medium may advantageously contain an anti-corrosive agent and in addition the formed protective film is burned from 0.25 to 3 hours at a temperature of from 100.degree. to 500.degree. C.