LUO Haihui, ZHANG Fucheng, ZHANG Ming

(College of Materials Science and Engineering, Yanshan Univers ity,Qinghuangdao 066004)

Abstract: Res idual stresses in alumina/mullite compos ites were measured by X- ray diffraction and the resultant values were validated by calculating. The res idual stresse was in linear relation with the mullite content when it was low. The res idual stress - es in the alumina matrix and on the mullite particles as well as their effect on crack growth were analyzed by modelling. The tensile stress in matrix introduced by mullite particles made the cracks incline to extend into the matrix. Trans ition of fracture mode was observed and the percentage of transgranular fracture (PTF) as a function of the matrix stresses was figured out. The coincidence relation of mullite content, matrix stresses and PTF was then established. The results provide some basic foundation for preparation and property studying for ceramic composites .

Keywords: composite, alumina, mullite, residual stress , fracture mode