Influence of plastic deformation by high-pressure torsion on the crystallization kinetics of a Pd40Ni40P20 bulk metallic glass

Abstract

The influence of high-pressure torsion on the crystallization behavior of the pre-annealed Pd40Ni40P20 bulk metallic glass was investigated by differential scanning calorimetry and fluctuation electron microscopy. Calorimetry shows that deformation splits the single main crystallization peak into a two-step crystallization process including a primary and a main peak. This is in line with fluctuation electron microscopy, which shows a reduction of ordering upon deformation. The overall activation energy and the local activation energy of the crystallization were analyzed by the Kissinger and Kissinger-Akahira-Sunose methods, respectively. The primary crystallization peak occurs at a lower temperature but shows a higher activation energy due to the drastically accelerated atomic mobility. Deformation can accelerate the crystallization process by increasing the nucleation rate.