METHOD OF FORMING BLACK YTTRIUM OXIDE SPRAYED COATING AND MEMBER PROVIDED WITH BLACK YTTRIUM OXIDE SPRAYED COATING

摘要

A technology for forming a black yttrium oxide sprayed coating from a white Y2O3 spray powder material. In this technology, plasma spraying of a white Y2O3 powder material for spray is carried out with the use of a mixed gas obtained by adding hydrogen gas to an inert gas, such as Ar or He, as a working gas for plasma/jet generation to thereby convert the material to black particles of the formula Y2O3-x having a portion of the oxygen of the Y2O3 powder lost by the strong reducing action of atomic hydrogen contained in plasma heat source. Thus, a black yttrium oxide sprayed coating is formed on a surface of base material.