Patent ID: 6096381
Filing Date: 2000-08-01
Classification: C23C

Abstract:
A method for forming a thermal barrier coating system, the method comprising the steps of:providing a superalloy substrate;forming a bond coat on the substrate by depositing a metal powder by high velocity oxy-fuel spraying, the metal powder consisting of particles of a metallic material chosen from the group consisting of aluminum-containing intermetallics, chromium-containing intermetallics, MCrAl and MCrAlY, at least a portion of the particles having a diameter of at least 40 .mu.m, the bond coat being characterized by a surface roughness of at least 350 microinches Ra that is attributable to the particles having a diameter of at least 40 .mu.m being incompletely melted during deposition;heat treating the bond coat in a vacuum or inert atmosphere at a temperature of about 950.degree. C. to about 1150.degree. C. for a duration of about one to about six hours to diffusion bond the metal powder and densify the bond coat without oxidizing the bond coat and the particles of the metal powder, the bond coat being characterized by a density of at least about 95% of theoretical density and theplasma spraying a ceramic layer on the bond coat.