Improvement in mechanical properties of a Zr-Based bulk metallic glass by laser surface treatment.
Résumé
In this work, surface modification of Zr55Cu30Al10Ni5 bulk metallic glass for improving the mechanical properties was carried out by employing laser surface melting (LSM) treatment. The structures and thermal properties of the as-cast and LSM treated samples were characterized with high energy synchrotron diffraction and differential scanning calorimeter, respectively. After the laser surface remelting, the Zr55Cu30Al10Ni5 alloy still consisted of fully amorphous structure. In comparison to the as-cast Zr-based alloy without distinct plasticity, the LSM treated one exhibited compressive plastic strain of 5.3% prior to fracture. The improvement in mechanical behavior of the LSM treated metallic glass may be resulted from complex residual stress distributions and increase in free volume in the surface layer induced by LSM treatment.