Metallic glasses respond to radiation in qualitatively different ways than crystalline solids. I will describe two distinctive mechanisms of radiation response in metallic glasses, identified through a series of ½ billion-atom simulations using molecular dynamics. In the first, inter-nuclear scattering causes localized melting and quenching at rates approaching 1014 K/s, giving rise to nanoscale “super-quenched zones” (SQZs) with exceptionally high free volume. In the second, rapid volumetric expansion in regions of localized melting generates intense stress pulses that cause polarized plastic deformation in adjacent material. These insights lead to the construction of a parameter for predicting the radiation response of amorphous materials that may be used in the selection of metallic glasses for applications ranging from nuclear waste storage to ion beam materials modification.
MIT Department of Materials Science and Engineering, Cambridge MA,