OsCo-based high-temperature bulk metallic glasses with robust mechanical properties
Jiazi Bi, Xinquan Wei, Xiaobin Liu, Ran Li, Ruijuan Xiao, Tao Zhang
Abstract
A family of novel Os–Co–Ta–B high-temperature bulk metallic glasses (HTBMGs) was fabricated by introducing high-modulus refractory metal Os (50 wt% at least) and strong-covalent metalloid B (up to 40 at%). These OsCo-based HTBMGs exhibit high glass transition temperature up to 1028 K and high Vickers microhardness up to 17.6 GPa. The compressive strength can reach up to 6.0 GPa at room temperature and even over 4 GPa at 873 K (a new record for strength of metallic materials at this high temperature so far). The impressive strength is attributed to the strong bond characteristics especially for Ta–Os and B–B bonds. By combining experimental and theoretical analysis for the relationships among alloy composition, atomic structure and the related properties, a promising route was provided to design HTBMGs with desirable properties. The castable OsCo-based HTBMGs with superior mechanical properties and high thermal stabilities are significant for high-temperature applications as advanced structural materials.