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The wetting characteristics of Ti 32.8 Zr 30.2 Fe x Cu 14.3- x Be 22.7 (at.%, x = 0, 2.5, 5.3) bulk metallic glasses (BMGs) with W substrate are conducted using the sessile drop method at different temperatures. The effect of Fe content on wettability is systematically studied. At a given temperature, contact angle initially rises and subsequently declines as the Fe content increases from 0 at.% to 5.3 at.%. Optimal wettability is observed in BMGs devoid of the Fe element. This is attributed to the influence of Fe addition on the elemental diffusion behaviors and two-phase interfacial morphologies during wetting. The addition of 2.5 at.% Fe leads to a significant accumulation of Ti element at the wetting interface and prevents the wetting process. As the Fe content increases to 5.3 at.%, the conspicuous abundance of Fe in the glass phase together with the diffused Cu in W substrate determines the wettability of the system. These findings not only reveal the influence of Fe content on the wetting properties of the TiZr-based BMGs/W system but also provide a theoretical basis for the preparation of ex-situ BMG composites. • The contact angle first increases and then decreases with increasing Fe content. • Optimal wettability is observed in BMGs devoid of the Fe element. • Fe content has a significantly influence on the interface morphology of wetting. • Diffusion behavior of atomic clusters directly determines interfacial wettability. [ABSTRACT FROM AUTHOR]

Bulk metallic glass composites containing in-situ formed 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 of in-situ formed 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 Zr 56.9 Ti 18.8 Cu 7.4 Ni 5.7 Be 11.3 BMGC 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, the in-situ formed 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. [ABSTRACT FROM AUTHOR]