Graded reactive element containing aluminide coatings for improved high temperature performance and method for producing

摘要

A diffusion aluminide coating having a graded structure is applied over a nickel base superalloy substrate. The coating has an inner region of a diffusion aluminide adjacent to the substrate rich in a reactive element, typically Hf, Si or combinations of the two. The near surface region is a diffusion aluminide which is substantially free of reactive elements. Such coatings when used as bond coats in thermal barrier coating systems exhibit improved spallation performance.