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

ABSTRACT

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°C were carried out. Uniaxial tensile and compressive behaviours at temperatures with range from RT to 400°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.

KEYWORDS:

• Thermomechanical
• metallic glasses
• mechanical properties
• fatigue

Additional information

Funding

This work is funded by the National Natural Science Foundation of China [grant numbers 51875241, 51505180, U1601203], Jilin Province Science and Technology Development Program Project (20190302078GX, 20180201126GX, 20170101134JC) and China Postdoctoral Science Foundation Funded Project [grant number 2017T100205].