Enhanced strength and plasticity of a Ti-based metallic glass at cryogenic temperatures

Conventional crystalline materials usually exhibit a ductile to brittle transition behaviour at low temperatures. An increase in the strength is always accompanied by a decrease in the plasticity. Here the authors report on a significant enhancement in both compressive strength and plasticity of a Ti-based bulk metallic glass (BMG) deformed at low temperatures. The ductilization of the BMG system can be evidently attributed to the formation of dense shear bands and the rotation mechanism of shear bands. The cryogenic surroundings can effectively slow down the mobility and diffusion of the atoms and consequently, suppress the nucleation and growth of nanocrystals during the deformation process, allowing the simultaneous improvement in the mechanical responses of the glassy alloy to compressive loading far below the ambient temperature.