Effect of surface modifications on shear banding and plasticity in metallic glasses : An overview

Previous results on the effect of surface structures, including intrinsic microstructural modification and extrinsic coating, on the plastic strain in tension, compression and bending were summarized. Sample confinement and residual stresses produced by various techniques such as shot peening and laser surface melting on the delay/retardation of shear band initiation and propagation were discussed. In the case of surface coatings, ductile monolayer and bilayers coatings were deposited on metallic glasses and tested, and the bilayers always exhibited better performance, suggesting that a graded structure was always beneficial. In this overview, the theoretical basis for multi-staged deformation of shear banding under compression and the physical origins for shear-band instability were also discussed for the benefit to develop an effective coating on metallic glasses for plasticity improvement.