Method of making a coated cemented carbide body and resulting body

A chemical vapor deposition method of making an aluminum oxide-coated body wherein a cemented carbide or ceramic substrate is contacted with a gas containing an aluminum halide and hydrolyzing and/or oxidizing agent at a temperature in the range of from 700.degree. to 1200.degree. C., characterized in that methane gas is added to the gas in an amount sufficient to result in at least 85% of the aluminum oxide being in the kappa form.

Coated body containing at least one metal carbide or ceramic compound on which body there is applied by chemical vapor deposition at a temperature of from 700.degree. to 1200.degree. C. at least one thin, even, wear resistant surface layer consisting essentially of a ceramic oxide, characterized in that the ceramic oxide layer is evenly distributed on the body and at least one of the ceramic oxide layer and the surface zone of the body containing at least one member selected from the group consisting of sulfur, selenium, tellurium, phosphorus, arsenic, antimony and bismuth in an amount sufficient to achieve said even distribution.

Chemical vapor deposition method of making a body comprising a substrate or core of a non-metal and at least one thin, wear resistant sufface layer consisting essentially of a ceramic oxide in which the substrate is contacted with a gas containing one or more halides of a metal or metals forming the ceramic oxide and a hydrolyzing and/or oxidizing agent at a temperature in the range of from 700.degree. to 1200.degree. C. to form by chemical vapor deposition the ceramic oxide layer, characterized in that an amount of a dopant selected from the group consisting of sulfur, selenium, tellurium, phosphorus, arsenic, antimony, bismuth and mixtures thereof is added to the gas whereby the layer is evenly distributed over the body.

Coated body containing at least one non-metallic compound on which body there is applied by chemical vapor deposition at a temperature in the range of from 700.degree. to 1200.degree. C. at least one thin, even, wear resistant surface layer consisting essentially of a ceramic oxide characterized in that the cermaic oxide layer is evenly distributed over the body and at least one of the ceramic oxide layer and the surface zone of the body containing at least one member selected from the group consisting of sulfur, selenium, tellurium, phosphorus, arsenic, antimony and bismuth in an amount sufficient to achieve said even distribution.