THE PROTECTION OF METALS AT HIGH TEMPERATURES 620451
High-temperature performance of coated metal systems is affected by reaction of the coating to the environment and interaction between the coating and substrate. Both coating and substrate selection are important. Coating-application techniques are equally important to material parameters in establishing systemic performance. Intermetallic diffusion coatings (silicides, aluminides) are of principal interest in protecting the refractory metals (columbium, molybdenum, tantalum, tungsten) from oxidation. Major application techniques include vapor deposition and slurry processes. Use of coated molybdenum parts has been reported; however, the general status of coated refractory metals is still largely developmental.