Characterization of machined ceramic surfaces with acoustic microscopy

: Pangraz, S.; Arnold, W.; Weides, G.

Abstract
Beside the advantages of advanced ceramics like high working temperature and chemical resistance the low ductility of ceramics is one of their major disadvantages. The low Kic of ceramics in comparision to ductile materials entails spontaneous crack growth at the same loading conditions for smaller defects. Thus holds in particular for the surface near zone. Therefore, the quality of the finished surface is imporatnt in order to prevent damage during loading. The final machining of the ceramic surface plays a central role. Here, two different grinding methods (alternating and creep feed grinding) are compared by mechanical testing and nondestructive testing methods.