Thermal Stability and Transformation-mediated Deformability of Cu-Zr-Al-Ni Bulk Metallic Glass Composite

The glass-forming ability and the thermal stability of Cu45Zr45Al5Ni5 metallic glass were systematically investigated by the differential scanning calorimetry. The activation energies for the glass transition and the onset crystallization and the crystallization peak were calculated to be 255.1, 308.7 and 311.5 kJ/mol, respectively, while the corresponding liquid fragility was determined to be 23.4. By controlling the casting process, Cu45Zr45Al5Ni5 bulk metallic glass composite with the presence of ductile B2 CuZr phase was fabricated. The composite shows a pronounced plastic strain of 6.8 ± 0.05% with obvious work hardening, which results from the formation of multiple shear bands and the deformation-induced martensitic transformation.