Oxidation behavior of a Ti_(16.7)Zr_(16.7)Hf_(16.7)Cu_(16.7)Ni_(16.7)Be_(16.7) high-entropy bulk metallic glass

摘要

In this study, the oxidation behavior of a supercooled Ti16.7Zr16.7Hf16.7Cu16.7Ni16.7Be16.7 HE-BMG was investigated. The mass gain of specimens during oxidation is very limited, and the maximum value is lower than 0.08 x 10(2) g/cm(2) after two hours of insulation. With the insulation duration prolonging, the mass gain decreases, indicating that the oxides formed are not stable and could decompose after long-term heating. Meanwhile, the oxidation kinetics doesn't follow the parabolic rate law, indicating that it is not a diffusion-controlled process. Even for specimens oxidized at 713 K for 120 min, they are still fully amorphous. No surface precipitates, as well as continuous oxide scale structures, are formed even after oxidation for 120 min at 753 K. Therefore, it is indicated that this HE-BMG has strong thermal stability and oxidation resistance, which is much promising for thermoplastic forming. (C) 2018 Elsevier B.V. All rights reserved.