Effect of Porosity on Properties of Nanocrystalline Materials

Grain Size Dependent Mechanical Properties in Nanophase Materials

It has become possible in recent years to synthesize metals and ceramics under well controlled conditions with constituent grain structures on a nanometer size scale (below 100 nm). These new materials have mechanical properties that are strongly grain-size dependent and often significantly different than those of their coarser grained counterparts. Nanophase metals tend to become stronger and ceramics are more easily deformed as grain size is reduced. The observed mechanical property changes appear to be related primarily to grain size limitations and the large percentage of atoms in grain boundary environments. A brief overview of our present knowledge about the grain-size dependent mechanical properties of nanophase materials is presented.