Static and cyclic mechanical behaviours and fracture mechanisms of Zr-based metallic glass at elevated temperatures

To comprehensively understand the quantitative mechanical-thermal properties and fracture mechanisms of Zr-based bulk metallic glass (BMG), by using self-made miniature tensile/compressive device and motor-piezoelectric coupling driven fatigue device, a series of static and dynamic mechanical tests at elevated temperatures of bulk Zr55Cu30Al10Ni5 BMG with glass transition temperature T-g of 411 degrees C were carried out. Uniaxial tensile and compressive behaviours at temperatures with range from RT to 400 degrees C were experimentally obtained by means of digital speckle correlation analysis, the estimation of Young's modulus and fracture strengths as a function of the applied temperatures were investigated. The static and cyclic fracture morphologies at various temperatures were obtained to describe the mechanical-thermal fracture mechanisms in detail. The coupling effect of loading types, stress-induced temperature rise and applied temperature on the evolution of cleavage features, dimples, vein patterns and shear softening behaviours were investigated.