Effect of nanocrystalline SiC addition on reactive SPS and oxidation resistance of Ta4HfC5 ceramics

Potentials of relatively low-temperature (1700 and 1800 °C) production of ceramic materials Ta4HfC5 and Ta4HfC5 -30 vol% SiC by reactive spark plasma sintering of highly dispersed powders Ta2O5-HfO2-C and Ta2O5-HfO2-C-SiC, respectively, were studied. It was shown that the introduction of silicon carbide led, not only to the stimulation of the consolidation process and the formation of a solid solution of Ta4HfC5 composition, but also to an increase in the oxidation resistance of the carbide ceramics. Besides thermal analysis in an air current, the oxidation resistance of the obtained ceramic materials of Ta4HfC5 and Ta4HfC5-30 vol%SiC composition was estimated by exposure of their surface to laser radiation in atmospheric air.