The effects of devitrification on the mechanical properties of Cu 46 Zr 54 metallic glass

TLDR: In this paper, the room temperature mechanical properties of the metallic glass Cu46Zr54 have been investigated as a function of aging time at 375°C (15°C belowT g).

Abstract: The room temperature mechanical properties of the metallic glass Cu46Zr54 have been investigated as a function of aging time at 375°C (15°C belowT g). The results indicate that the tensile fracture stress and hardness of this material can be changed by such thermal processing. Fracture stress and hardness are increased with short times at temperature by structural relaxation. Also, the presence of a very small volume fraction of crystalline phase causes the shear stiffness of the material to increase markedly providing an additional increase in fracture stress and hardness. Continued devitrification causes embrittlement and the decrease of fracture stress, as predicted by the model of two-phase materials; however, hardness continues to increase, reflecting the increasing volume fraction of the harder crystalline phases. Embrittlement and decreasing fracture stress are enhanced by the stress concentration effect at the crystallites which causes void formation and growth.