High-Temperature Reliability of Advanced Ceramics

Abstract

This paper describes high-temperature reliability, particularly creep and creep rupture behavior of three engineering ceramics—silicon nitride, silicon carbide, and alumina-based silicon-carbide-particulate ceramics—which are considered the most potential candidates for the use of blades of high-efficiency ceramic gas turbine. The structural reliability of silicon nitride is very often limited due to the softening of glassy phases formed at grain boundaries. On the other hand, silicon carbide, which generally does not contain glassy phase at the grain boundaries, shows excellent creep resistance even at very high temperatures. Finally, it is shown that creep resistance of alumina can be markedly improved by dispersing nano-sized silicon carbide particles into the grain boundary.