Ambient temperature embrittlement of a Zr-based bulk metallic glass

Three-point bending experiments were performed on Zr52.5Cu17.9Ni14.6Al10Ti5 (Vit105) bulk metallic glass (BMGs) over a wide range of ambient temperatures varying from the liquid nitrogen temperature (77 K) to about boiling water temperature (370 K). The results demonstrated that the flexural strength of the Zr-based BMG monotonously increased with decreasing of test temperature, whereas plastic deformation ability displayed a maximum at a moderate temperature (about room temperature). That is, the plastic deformation ability was deteriorated by either higher or lower temperature than room temperature through affecting shear band nucleation and propagation within materials respectively.

► Flexural strength of a Zr-based bulk metallic glass (BMGs) under ambient temperature follows the (T/Tg)2/3 softening law proposed by Johnson and Samwer (Phys. Rev. Lett. 95 (2005) 195501), while the plastic strain show the monotone relationship with the ambient temperature and appears a peak at a moderate temperature. ► Lower and higher temperature (only boiling water temperature) will both deteriorate their plastic deformation ability through affecting shear band nucleation and propagation within materials respectively.