Abstract: A process for forming a diffusion aluminide coating on an article, such as a component for a gas turbine engine. The process is a vapor phase process that generally entails placing the article in a coating chamber containing an aluminum donor material, without any halide carrier or inert filler present. The aluminum donor material consists essentially of about 20 to about 70 weight percent aluminum, with the balance being chromium or cobalt. While the article is held out of contact with the donor material, coating is initiated in an inert or reducing atmosphere by heating the article and the donor material to vaporize the aluminum constituent of the donor material, which then condenses on the surface of the article and diffuses into the surface to form a diffusion aluminide coating on the article.

Abstract: A process for reclaiming aluminum alloy donor from a vapor phase deposition process used to form a diffusion aluminide coating on a component, such as the high-temperature superalloy components of gas turbine engines. The process generally entails recycling a particulate aluminum alloy donor material that, as a result of having been used as the donor material for depositing a diffusion aluminide coating on an article by vapor phase deposition, particles of the donor material comprise an aluminum alloy core encased in an aluminum-depleted shell. The process generally entails tumbling the donor material in a manner that removes the aluminum-depleted shell, followed by sieving the donor material to remove shell fragments and undersized particles.