QUANTITATIVE STRESS MAPPING IN ALUMINA COMPOSITES BY OPTICAL FLUORESCENCE IMAGING

摘要

Internal residual stresses exist in almost all polycrystalline materials and in many cases exert a profound influence on mechanical and physical behavior. In inherently brittle ceramics and ceramic composites, toughening mechanisms often depend sensitively on localized residual stresses. However, despite their prominence few studies are available which provide a detailed characterization of the local spatial variation of residual stress fields in ceramics and their composites. In this study, we report on the spatially resolved mapping of local residual and applied stresses in polycrystalline alumina and a variety of Al_20_3-SiC_w composites.