Thermal behavior of newly developed Zr33Hf8Ti6Cu32Ni10Co5Al6 high-entropy bulk metallic glass

Abstract

In this study, new non-equiatomic high entropy bulk metallic glass (HEBMG) Zr33Hf8Ti6Cu32Ni10Co5Al6 was developed according to the Cu47Zr47Al6 prototype BMG. Kinetic studies were performed with non-isothermal DSC for the BMG and the HEBMG, and their thermal properties were compared. Calculation of activation energies by different methods indicated that Eg is higher for the HEBMG than the BMG, while Ep is lower for the HEBMG than the BMG, and Ex is similar for both alloys. The values of structural relaxation enthalpy for the BMG and the HEBMG were 4.95 J/g and 8.19 J/g, respectively. Free volume was calculated at room temperature and Tg. By doing so, the direct correlation between fragility, structural relaxation enthalpy, diffusion, and free volume was shown. Using a compression test at room temperature, a 58% improvement in plastic strain was obtained for HEBMG, which confirmed the calculations. (c) 2021 Elsevier B.V. All rights reserved.