Evaluate the effect of laser shock peening on plasticity of Zr-based bulk metallic glass

• We report that LSP can improve the bending plasticity of Zr-based BMG.
• LSP facilitates the formation of shear bands in BMG.
• The high level of strain concentration promotes shear bands formation.
• The larger the laser irradiated region is, the better the plasticity will be.

The effect of laser shock peening (LSP) on mechanical properties, especially the plasticity of a typical Zr-based bulk metallic glass (BMG) had been investigated. The surface treatment introduced by successive laser pulses facilitated the formation of shear bands and promoted the plastic deformation of BMG. Experimental investigations of the bending deformation behavior were performed by three-point bending test at room temperature. It was found that the LSP pretreatment could improve the plasticity. The shear bands in fracture surface of laser peened sample were increased which could be observed by SEM. Logarithmic strain and stress distributions during bending deformation were predicted by finite element analysis. The high level of strain concentration in peened sample represented the increasing possibility of shear band formation which was beneficial to enhance plasticity. Corresponding with the strain distribution, the stress in peened sample was also increased which would enhance the ability of resisting a larger bending load force. Besides, simulation results clearly showed the logarithmic strain evolution of the beams with different laser irradiated regions throughout the bending process. The results indicated that the larger the laser irradiated region was, the better the plasticity of BMG would be.