Developing β-type bulk metallic glass composites from Ti/Zr-based bulk metallic glasses by an iteration method

摘要

AbstractBulk metallic glass composites containingin-situformed β-Ti/Zr phases (β-type BMGCs), which exhibit a good combination of strength and plasticity, were generally developed by adding β-stabilizers, such as Nb, Ta, V, etc., into Ti/Zr-based bulk metallic glasses (BMGs). In this work, an iteration method is proposed to develop β-type BMGCs from Ti/Zr-based BMGs, and the compositions of BMGCs can be designed by “the composition ofin-situformed β phase (the iterative variable)?+?the composition of BMG”. Due to the fast elemental diffusions between the β phase and the (supercooled) liquid phase, the iteration method can develop β-type BMGCs in which both phases can maintain a mutual (metastable) equilibrium during solidification. The procedures of the iteration method and its underlying thermodynamic and kinetic principles are discussed, and a Zr56.9Ti18.8Cu7.4Ni5.7Be11.3BMGC was developed from Vitreloy 1 by using the iterative method. As compared with β-type BMGCs developed by the conventional method, β-type BMGCs developed by the iteration method have two advantages: (i) the good glass-forming ability of the initial BMGs can be largely inherited by the glassy matrices in BMGCs; (ii) without adding β-stabilizers, thein-situformed β phases are more likely to be metastable. The current iteration method is of scientific significance on improving plasticity of Ti/Zr-based BMGs and developing new β-type BMGCs.Graphical abstractDisplay OmittedHighlights?An iteration method was proposed to develop β-type BMGCs from Ti/Zr-based BMGs.?Thermodynamic and kinetic principles underlying the iteration method were discussed.?A metastable β-type BMGC was developed from Vitreloy 1 in Zr–Ti–Cu–Ni–Be system.?The developed β-type BMGC exhibits improved plasticity as compared with Vitreloy 1.]]>