9523028 Wu This project is to study the local heterogeneities in polycrystalline materials and their effect on crack initiation. In particular, certain non-equilibrium grain boundary structures and morphologies and their associated nucleation stresses and resulting crack characteristics will be investigated. There exists some evidence that these non-equilibrium grain boundaries are found in submicron-grained and nanocrystalline materials. The results will be generally applicable to metallic systems and to certain ceramic materials. ***
