Nanocrystallization in a shear band: An in situ investigation

Preferential nanocrystal formation in shear bands that occurred upon applying a tensile strain on an Al-rich metallic glass has been analyzed in situ in a transmission electron microscope as a function of time after the shear band initiation and as a function of local heating. The results indicate the presence of a transient period before nanocrystal formation sets in, as well as the necessity of thermal activation and further show that nanocrystals developed only within the shear bands. These results support models that explain nanocrystal formation in shear bands based on an increased local mobility. (C) 2011 American Institute of Physics. [doi:10.1063/1.3602315]