Research on thermoplastic formability and nanomoulding mechanism of lightweight Ti-based bulk metallic glasses

The poor thermoplastic formability is one of the bottlenecks in restricting the wide application of Ti-based bulk metallic glasses. In this study, alloying method was adopted to improve the thermoplastic formability of a lightweight Ti–Zr–Be bulk metallic glass (BMG). Different combinations of alloying elements, alloying routes and alloying contents have been tried to optimize the alloy composition. S parameter was found to be an effective indicator for evaluating the thermoplastic formability of the studied Ti-based bulk metallic glasses. A Ti₄₅Zr₂₀Be₃₀Fe₅ alloy, which possesses unique thermoplastic formability, has been successfully developed. A nanomoulding processing map for Ti₄₅Zr₂₀Be₃₀Fe₅ alloy has been constructed. To reduce the capillary effect, a wetting layer has been introduced during the nanomoulding process. Finally Ti-based BMG nanorods have been successfully fabricated in air, which further confirms the effectiveness of the proposed processing map and the superior thermoplastic formability of developed Ti₄₅Zr₂₀Be₃₀Fe₅ BMG.