Patent ID: 6332931
Filing Date: 2001-12-25
Classification: C23C

Abstract:
A process for forming a diffusion aluminide-hafnide coating, the process comprising the steps of:placing an article in a coating chamber containing a halide activator and at least one donor material, the donor material collectively consisting essentially of at least 0.5 weight percent hafnium and at least 20 weight percent aluminum with the balance being a material with a higher melting point than aluminum, both the hafnium and the aluminum being available at the surfaces of the donor material, the article being out of contact with the halide activator and the donor material; and thenin an inert or reducing atmosphere, heating the article, the halide activator and the donor material to react the hafnium and aluminum at the surfaces of the donor material with the halide activator and produce a halide vapor that reacts at the surface of the article to form a diffusion aluminide-hafnide coating on the surface.