SHEAR-BAND DYNAMICS IN METALLIC GLASSES

Abstract

Shear banding is a localized plastic deformation form that wildly exist in amorphous systems, and plays the decisive role in controlling the failure and plasticity. Due to the localization in space and instantaneous in motions, clarifying the map of shear bands is still a challenge mission. For traditional amorphous systems as rocks, colloid, oxide glasses and polymers, the studies on shear bands are impeded due to the poor mechanical properties or complex structures of these systems. In recent years, the developments of metallic glasses (MGs) overcome this barrier with the abundant mechanical experiments on shear bands in laboratories, which greatly promotes the insights to shear bands. In addition, the dynamics of shear bands have a significant influence to the mechanical properties and behaviors of MGs, which is also of significant importance for understanding the deformation mechanisms of MGs. The insights for the structural origin, morphology, affect area, properties and motions of shear bands has made great progress. With the investigations on MGs, shear mands are found inhomogenous in space distribution and non-steady in time. The behaviors of shear bands show a similarity with that of the complex systems in nature as well as physic areas. This article mainly reviews our recent studies on the complex behaviors of shear bands in MGs, including the serration follow behaviors and the self-organizing criticality (SOC) behaviors of shear bands. The models that quantify these behaviors of shear bands, such as stick-slip model, machine-sample coupling model, are also introduced. The review also identified the key questions remaining to be answered, and presents an outlook for the field.