Three coating systems were developed that protected 60 mil tungsten sheet from oxidation in air at elevated temperatures. These composites, applied by the vacuum pack process, were; silicon-tungsten; titanium zirconium silicon tungsten, and; titanium zirconium-boron silicon-tungsten. A laboratory scale process for application of each coating to tungsten sheet was developed and optimized. Oxidation characteristics of the coated systems in air under various static and cyclic conditions were determined from 1600° to 3650° F with several hours protection being achieved under cyclic conditions at 3550° F. Tensile tests were conducted on two of the three systems at regular temperature increments from room temperature to 3300° F under various environmental conditions. Stress oxidation, thermal shock, and hot gas erosion tests were also con ducted on the diffraction patterns were determined on the silicon-tungsten and titanium zirconium silicon-tungsten composites in the coated and exposed conditions. (Author).