Amorphous Silicates -- Time-Current Superposition and the Dynamics of Plastic Flow in the Glassy State

Abstract

Electron irradiation enables quantitative control over the plastic flow dynamics of silicate glasses, even far below the glass transition temperature. Through stress-relaxation experiments spanning ambient to near-glass-transition temperatures, we uncover a time-current equivalence that grants direct access to steady-state plastic flow over five decades in strain rate. This equivalence allows reconstruction of the intrinsic plastic-flow curve and quantitative assessment of the roles of network connectivity and temperature. Notably, the observed temperature dependence reveals a striking discrepancy with existing theoretical frameworks, highlighting the need for a comprehensive model of plastic flow dynamics in the glassy state.