Investigations of residual stresses in ceramic components

Fundamental principles and many details about formation and effects of residual stresses in metals are known. In the case of engineering ceramic materials with their increasing fields of application, the influence of these stresses on potential use and on reliability of components is of great interest as well. The non-destructive method of X-ray stress analysis approves to be a suitable tool to determine the residual surface stress state. This paper presents the results of investigations on specimens and components made from silicon carbide and silicon nitride. The aim of this experimental work was to evaluate the effect of sintering conditions, of heat treatment, of shaping and machining and of joining (metals/ceramics or ceramics/ceramics) on the resulting residual stresses. Rectangular bars, rings, hollows, cylinders and trubocharger rotors were tested. (IWM)