Quantitative stress mapping in alumina composites by optical fluorescence imaging

摘要: Abstract Internal residual stresses exist in almost all polycrystalline materials and many cases exert a profound influence on mechanical physical behavior. In inherently brittle ceramics ceramic composites, toughening mechanisms often depend sensitively localized stresses. However, despite their prominence few studies are available which provide detailed characterization of the local spatial variation stress fields composites. this study, we report spatially resolved mapping applied alumina variety Al 2 O 3 SiC w Stress is based well established method measuring shifts characteristic optical fluorescence lines produced by Cr 3+ impurities matrix. Novel illumination imaging optics used to collect up 15,000 measurements from an area approx. 1 mm . Detailed maps generated produce vivid quantitative indication complex present these materials. The additional effect non-uniform field ahead blunt notch also measured. Results discussed context thermal expansion anisotropy within phase, differences between SiC-reinforcement matrix, distribution whiskers. mean value fluctuation resultant estimated extension recent stochastic mechanics models compared measured values.