标题：Dual self-organised shear banding behaviours and enhanced ductility in phase separating Zr-based bulk metallic glasses
作者：Zhang, Z. Q.; Song, K. K.; Sun, B. A.; Wang, L.; Cui, W. C.; Qin, Y. S.; Han, X. L.; Xue, Q. S.; Peng, C. X.; Sarac, B.; Spieckerm 更多 作者机构：[Zhang, Z. Q.; Song, K. K.; Wang, L.; Cui, W. C.; Qin, Y. S.; Han, X. L.; Xue, Q. S.; Peng, C. X.] Shandong Univ Weihai, Sch Mech Elect & Informat Eng 更多
通讯作者：Song, K K
通讯作者地址：[Song, KK; Wang, L]Shandong Univ Weihai, Sch Mech Elect & Informat Engn, Weihai, Peoples R China;[Sun, BA]Nanjing Univ Sci & Technol, Herbert Gleiter 更多
关键词：Metallic glasses; mechanical properties; plasticity; phase separation;; shear bands
摘要：The multiplication and interaction of self-organised shear bands often transform to a stick-slip behaviour of a major shear band along the primary shear plane, and ultimately the major shear band becomes runaway and terminates the plasticity of bulk metallic glasses (BMGs). Here, we examined the deformation behaviours of the nanoscale phase-separating Zr65-xCu25Al10Fex (x=5 and 7.5 at.%) BMGs. The formation of multi-step phase separation, being mainly governed by nucleation and growth, results in the microstructural inhomogeneity on a wide range of length-scales and leads to obviously macroscopic and repeatable ductility. The good deformability can be attributed to two mechanisms for stabilizing shear banding process, i.e. the mutual interaction of multiple shear bands away from the major shear band and the delaying slip-to-failure of dense fine shear bands around the major shear band, both of which show a self-organised criticality yet with different power-law exponents. The two mechanisms could come into effect in the intermediate (stable) and later plastic deformation regime, respectively. Our findings provide a possibility to enhance the shear banding stability over the whole plastic deformation through a proper design of microstructure heterogeneities.