Improving plasticity of the Zr₄₆Cu₄₆Al₈ bulk metallic glass via thermal rejuvenation

In this paper, effects of cryogenic thermal cycling on deformation behavior and thermal stability of the Zr₄₆Cu₄₆Al₈ bulk metallic glass (BMG) were studied. The results show that with the increase of the number of cryogenic thermal cycles (CTC), thermal stability remains almost unchanged, while the plasticity is increased, indicating that the cryogenic thermal cyclic treatment is an effective way to improve plasticity of metallic glasses without distinctly deteriorating thermal stability. Our analysis suggests that the increase in the defect density resulted from the cryogenic thermal treatments are responsible for the plasticity increment. Variation of yield strength can be well interpreted from microstructural percolation which affected by both density and characteristic volume of the defect sites.