Effect of laser shock peening on mechanical properties of Zr-based bulk metallic glass

In the present work, laser shock peening (LSP) has been used in improving the mechanical properties in Zr-based bulk metallic glasses (BMGs). The as-cast BMG samples were repeatedly peened on one-side and two-side surfaces. The deformation behavior was examined by three-point bending test. It was observed that the two-side peened sample had the best plasticity with a plastic deflection of 2.38 mm. The following stress analysis in bending process revealed that LSP induced residual stress contributed to improving flexural strength and flexural modulus of one-side peened sample. LSP induced residual stress was predicted by finite element analysis. Bending fracture surface morphology of BMGs was also been examined. It exhibited three different regions: compressive fracture region, neutral fracture region and tensile fracture region. Under the influence of LSP, different regions experienced different stress states. The reduction of long straight cracks and micro cracks as well as the uniform and compact appearance of striated vein-like patterns revealed that LSP was beneficial to improving the plasticity of BMG.