Brittle-to-Ductile Transition in Silicon Carbide

Observations of the microstructure and creep behavior of two commerical silicon carbides are presented. A combination of techniques has been used to characterize the microstructures. Sequential creep rupture testing has been carried out and scanning electron microscopy used to observe creep‐crack propagation and damage development. Basic theory for stress fields and creep rates around a crack tip is relatd to the observed brittle‐to‐ductile transition in these materials. Analogy with the brittle‐to‐ductile transition in steels is made and used to interpret the present observation.