INTERNAL FRICTION AND MECHANICAL PROPERTIES OF NEW CERAMICS

Stress amplitude and temperature dependences of internal friction in polycrystal and single crystal aluminas and aluminas subjected to thermal shock, were measured. Microcracks introduced by water quenching were detected by internal friction measurement. An increase ininternal friction due to softening at the grain boundary in the polycrystal alumina was observed above 600 C. The flexural strength and the hardness decreased with increasing internal friction