Fatigue Crack Growth Behavior and Mechanisms in α-β-SiAlON at High Temperature

摘要

Experimental results arc presented on subcritical crack growth under sustained and cyclic loads in gas pressure sintered α-β-sialon at 1200℃. High temperature subcritical crack growth behavior is examined by application of "controlled" surface cracking technique from Vickers indentations in bars loaded in 4-point bending Electron microscopy analysis in the crack-tip damage zone indicates that creep mechanisms such as cavity formation arc responsible for static fatigue and dislocation plasticity may play a certain role in high temperature cyclic fatigue fracture.