Homogeneous deformation of bulk metallic glasses

Homogeneous deformation of bulk metallic glasses (BMGs) is reviewed. Homogeneous deformation usually takes place at temperatures near and above the glass transition temperature. The deformation behavior depends upon strain rate. At low strain rates, BMGs behave like a Newtonian fluid (m = 1) but plastic flow becomes non-Newtonian at high strain rates. The non-Newtonian behavior is a result of microstructural instability, namely, the concurrent formation of nanocrystals in the amorphous matrix during deformation. Despite the difference in deformation behavior, BMGs usually show large ductility (over 300%) at temperatures in the supercooled liquid region.