Nanoindentation of CuZr metallic glasses subjected to thermal–pressure treatments

Abstract

In this work, nanoindentation tests were performed on CuZr MGs subjected to thermal–pressure treatments using molecular dynamics simulations, with pressures in the range of 0 to 20 GPa. No significant variations in the mechanical properties were observed. However, in the 20 GPa sample, shear bands (SBs) penetrated slightly more homogeneously compared to the other cases. Furthermore, a novel machine learning algorithm, called MultiSOM, revealed that the contact zone with the indenter was associated to high-shear atoms, whereas the inner and outer regions of the SBs were related to medium-shear and low-shear atoms, respectively. The 20 GPa case presented larger fractions of low-shear atoms, whereas the opposite behavior occurred in the 0 GPa case. Thus, despite the slight variation in mechanical properties, higher pressures still result in less-localized deformation. Overall, our results provide a quantitative description of plasticity in MGs using machine learning methods.