HIGH-TEMPERATURE HEAT-RESISTANT COATINGS FOR PROTECTION OF REFRACTORY METALS AND THEIR ALLOYS (OVERVIEW)

Abstract

Scientific publications on the methods of applying heat-resistant coatings to refractory metals, such as molybdenum, tungsten, niobium, tantalum, and their alloys, are analyzed. Vacuum activated diffusion hardening is considered as one of the most optimal methods of forming protective coatings. For niobium and tantalum, a molybdenum or tungsten layer is required, which is to be previously deposited by one of the three methods: vapor-phase deposition, condensation, or ion bombardment. The materials used for the production of protective coatings are studied: silicides, refractory metal borides, high-temperature oxides, and enamels.