Method for coating sliding surface of high-temperature member, high-temperature member and electrode for electro-discharge surface treatment

A high-temperature member having a sliding surface adapted to contact a second member under a high-temperature environment of 700° C. or more, and on which a coating layer of a constituting material of an electrode for an electro-discharge surface treatment, or a reactant of the constituting material, is formed by the electro-discharge surface treatment in which the electrode is used to generate a pulsed electro-discharge between the electrode and the sliding surface, and the coating layer includes pores, and the pores are filled with a solid lubricating material, and the solid lubricating material is Cr2O3, or a mixture of Cr2O3 and Si,

• wherein the electrode is a green compact that includes the constituting material that includes (i) a first coating material that is a cobalt-based alloy comprising 10% or more of chromium, by weight, and does not include 20% or more of nickel, by weight, or (ii) a mixture of the first coating material and a second coating material, wherein the first coating material comprises the chromium that oxidizes at a high temperature environment of 700° C. or more to form Cr2O3,
• wherein the second coating material is a material selected from the group consisting of any one of, or a mixture of, cBN, TiC, TiN, TiAlN, TiB2, WC, Cr3C2, SiC, ZrC, VC, B4C, Si3N4, ZrO2, and Al2O3, and wherein after the pores are filled with the solid lubricating material, the high-temperature member can be disposed so that the sliding surface of the high-temperature member contacts the second member, and wherein the sliding surface contacts the second member under the high temperature environment of 700° C. or more, and the chromium of the coating layer oxidizes under the high temperature environment of 700° C. or more to substantially increase formation of Cr2O3.