Effect of laser shock peening without absorbent coating on the mechanical properties of Zr-based bulk metallic glass

• The changes of microstructure of vit1 metallic glass after LSPwC are studied.
• The plastic deflection of vit1 metallic glass increase by 27% after LSPwC treatment.
• Crystallization and more free volume of vit1 metallic glass are induced by the process.
• Surface roughness is increased after LSPwC treatment.

In this work, laser shock peening without absorbent coating (LSPwC) was employed to Zr41.2Ti13.8Cu12.5Ni10Be22.5 (vit1) bulk metallic glass in order to improve its mechanical properties. The phase structure and thermal properties of the as-cast and LSPwC treated samples were characterized by X-ray diffraction, transmission electron microscope and differential scanning calorimeter. Three-point bending fracture tests of vit1 were performed on universal testing machine at room temperature with loading rate of 0.1 mm/min. The results showed that LSPwC enhanced the plasticity of vit1, and the plastic deflection increased by 23%. This enhancement could be attributed to the generation of crystalline phase and more free volume as well as the complex residual stresses induced by LSPwC. The optical profiling test showed that the LSPwC increased the surface roughness of vit1. Scanning electron microscope measurements on the fracture surface of vit1 revealed that high dense vein patterns were formed on cross section of the LSPwC treated sample.