The effect of simulated thermal cycling on thermal and mechanical stability of a Ti-based bulk metallic glass

The effects of simulated thermal cycling in vacuum in a temperature range of −196 °C to 150 °C on the thermal and mechanical stability of a lightweight Ti41Zr25Be29Al5 bulk metallic glass (BMG) has been studied. It has been found that the thermal cycling treatment has not induced obvious changes of thermal and mechanical properties of the BMG even after 400 cycles. No embrittlement evidence has been observed despite of that the structural relaxation enthalpy of the BMG has been decreased with the increment of cycling number. It indicates that the reduction of structural relaxation enthalpy which is related to the reduction of free volume within the glassy alloy, does not imperatively result in embrittlement. It shows the effect of thermal cycling of 400 cycles on the property and structural relaxation of the BMG is similar to but weaker than that of sub-Tg annealing at 150 °C for 30 days. The good stability of thermal and mechanical properties indicates that the lightweight BMG has the potential of applying in the experimental temperature range such as the low Earth orbit environment.