Validity of temperature and time equivalence in metallic glasses during shear deformation

Abstract

Competing internal and external time scales, which are determined by temperature and experimental sampling time—viz., reciprocal frequency—respectively, are essentials for understanding the physics of glasses and the glass transition. A temperature increase should ideally affect thermally activated phenomena in a similar manner as an increase of sampling time at constant temperature. We investigate the validity of this empirical principle by its manifestations in mechanical properties—viz., the temperature and strain rate dependence of the shear modulus and yield stress of a CuTi model glass in molecular dynamics computer simulations. In equivalence to the temperature-dependent glass transition, we identify a shear-rate-dependent glass transition below a certain threshold. Beyond that, deviations occur in a highly non-Newtonian regime.