Effect of deep cryogenic cycling treatment on shear transformation zone volume and size of Zr-based metallic glass

The study on the structure and mechanical properties of Zr 55 Al 10 Ni 5 Cu 29 Y 1 bulk metallic glasses (BMGs) indicates that deep cryogenic cycling treatment (DCT) is an effective method to improve room-temperature plasticity of BMGs containing trace rare earth elements. DCT not only increases the volume and size of STZs in BMGs, promotes the generation of multiple shear bands, but also reduces the maximum shear stress that occurs in pop-in events. Due to the internal stress generated during DCT, rejuvenation causes the larger volume and size of the shear deformation zone, which can promote the shear bands formation and generate multiple shear bands to accommodate plastic deformation. In different BMGs systems, the volume of STZs tends to decrease as v increases. STZ is more sensitive to the composition, and changes in trace elements can cause changes of the volume of STZs. Graphic abstract