Using large-scale molecular dynamics simulations

we predict that knock-on damage in irradiated metallic glasses yields spontaneous anisotropic deformation

i.e. shape change in the absence of externally applied loads. The root cause of this behavior is anisotropic plastic deformation around non-spherical thermal spikes. Such thermal spike-induced plasticity (TSIP) does not depend on electronic excitations and is distinct from the ‘ion hammer’ effect. Macroscale TSIP is predicted to occur under unidirectional heavy ion and neutron irradiation. The consequences of TSIP for potential applications of metallic glasses under irradiation are discussed.