Nanoscale multistep shear band formation by deformation-induced nanocrystallization in Zr-Al-Ni-Pd bulk metallic glass

摘要

A single Zr_(65)Al_(7.5)Ni_(10)Pd_(17.5) bulk metallic glass exhibits a large plastic strain of 6.6% during the compressive deformation process, which is attributed to the deformation mode with nanoscale multistep shear bands. We have observed that nanocrystals with a metastable fcc Zr_2Ni structure containing several distorted icosahedral clusters are arranged in a "bandlike" formation in the glassy matrix around the multistep shear bands. This is recognized as direct evidence of the novel phenomenon of the restraint of shear band propagation owing to the dynamic precipitation of the nanocrystals.