Improving the wear performance of a commercial Vit 1 amorphous alloy by a cryogenic cycling treatment

Abstract

A commercial Vit 1 amorphous alloy was processed by a cryogenic cycling treatment of different times. The phase structure, thermal, mechanical and wear properties were studied. Although the cryogenic cycling treatment does not change significantly the phase structure, it promotes thermal rejuvenation, i.e., the heterogeneity of the internal structure. The heterogeneous structure promotes initiation of multiple shear bands within the amorphous alloy to bring about dissipative deformation energy, which in turn increases the plasticity. Thanks to the plasticization, the wear properties were significantly improved by the cryogenic cycling treatment. In particular, the wear rate after 30 cycles of treatment (7.55 × 10–5 mm3/N m) decreases to about one third of the as-cast alloy (22.75 × 10–5 mm3/N m). The reason is that with the increase in plasticity, the wear mechanism of Vit 1 BMG changes from three-body abrasive wear to a synergistic mechanism of three-body abrasive wear and oxidative wear. Therefore, improving the plasticity of amorphous alloys by the cryogenic cycling treatment could be an effectively strategy to enhance the wear perfermance.