Influence of Heat Treatment Process on Tensile Fracture Behavior of Cu-Based Metallic Glass

Abstract

The Cu50Zr42Al8dumbbell-shaped alloy with original scale distance of 25 mm and diameters of 4.5 mm was prepared by the suspend melting-copper mould suction casting. The structure tensile performance testing and the fracture morphology observation of Cu50Zr42Al8BMG as-quenched and 400k/1h isothermal annealing were investigated, respectively. The deformation and fracture behavior of samples had been studied. The results showed that the structure of all samples were composed of amorphous phase and possess good glass formation abilitysample as-quenched is always in the elastic deformation stage during elongation and the tensile strength is 629MPa; however ,for specimen after 400k/1h isothermal annealing ,the yield phenomenon occurs before breaking and the maximum tensile strength is 755Mpa, and the same time, the maximum failure extensibility increases from 0.56% for sample as-quenched to 0.80% for 400k/1h isothermal annealing. The fracture pattern of test sample at annealing assumes venation pattern, which is similar to fractography of Cu50Zr42Al8BMG as-quenched, in addition, which appeared apparent viscous flow behavior and melting characteristics.