Vapor Phase Aluminide Coatings (VPA), also referred to as ‘above the pack’ or ‘gas-phase aluminide,’ is a thermal coating process that involves heating the part in an inert atmosphere along with a ‘donor’ material – which can be virtually any material that will alloy with aluminum. The donor material vaporizes as heat is applied and a coating is left on the component being processed. The VPA process can coat interior passages, making it a common process for aerospace parts such as turbine blades. VPA coating application also guards against the oxidization of nickel, steel, and other alloys. Byron Products can perform this process on parts 36 inches in height and up to 44 inches in diameter.