Shear band healing in amorphous materials by small-amplitude oscillatory shear deformation

Journal of Non-Crystalline Solids. 2021. Vol. 566. Article 120874.

Priezjev N.

The effect of small-amplitude periodic shear on annealing of a shear
band in binary glasses is investigated using molecular dynamics
simulations.  The shear band is first introduced in stable glasses
via periodic shear at a strain amplitude slightly above the critical
value, and then samples are subjected to repeated loading during
thousands of cycles at smaller amplitudes.  It was found that with
increasing strain amplitude, the glasses are relocated to deeper
potential energy levels, while the energy change upon annealing is
not affected by the glass initial stability.  The results of
mechanical tests indicate that the shear modulus and yield stress
both increase towards plateau levels during the first few hundred
cycles, and their magnitudes are greater for samples loaded at
larger strain amplitudes. The analysis of nonaffine displacements
reveals that the shear band breaks up into isolated clusters that
gradually decay over time, leading to nearly reversible deformation
within the elastic range. These results might be useful for
mechanical processing of metallic glasses and additive
manufacturing.

Keywords: additive manufacturing, molecular dynamics simulations

Publication based on the results of: Supercomputer technologies for atomistic modeling of physical processes in condensed matter (2021)