摘要 |
<p>A cemented carbide or ceramic substrate has a wearresistant composite ceramic coating comprising a doped twophase metal oxide layer comprising a fully dense, adherent, continuous metal oxide phase and a fully dense, adherent, discontinuous metal oxide phase. The continuous metal oxide phase comprises aluminum oxide, yttrium oxide, or zirconium oxide, and the discontinuous metal oxide phase comprises a dispersed, discrete second phase of aluminum oxide, yttrium oxide, or zirconium oxide, with the continuous metal oxide phase being of a different metal oxide from that of the discontinuous metal oxide phase. The continuous metal oxide phase, and/or the discontinuous metal oxide phase, contains a dopant comprising at least one member selected from the group consisting of sulfur, selenium, tellurium, phosphorus, arsenic, antimony, and bismuth. The wear-resistant composite ceramic coating is deposited on a cemented carbide or ceramic substrate by passing a first metal halide gas, a volatile oxidizing gas, a second metal halide gas, a carrier gas, and a dopant, over the substrate at a temperature of from about 700.degree. to 1250.degree.C., and at a pressure of from about 1 torr to ambient pressure, so that the continuous and discontinuous metal oxide phases are deposited on the substrate.</p> |