Development of Zr-based metallic glasses to utilize thermoplastic forming processes of engineering plastics

Abstract

Metallic glasses (MGs) have garnered significant attention for the possibility to use as advanced structural materials in recent decades. However, their high processing costs remain a major obstacle to their commercialization. This research offers a practical guideline to significantly reduce production costs through tailored alloy design and precise control of thermoplastic forming (TPF) process parameters. Specifically, we discovered commercially available MGs with a low glass transition temperature (Tg) can be developed in the Zr-rich alloy systems. Moreover, we addressed the challenge of maintaining a wide TPF window in Be-free Zr-based MGs while keeping Tg low. Our research has yielded the development of Be-free Zr-rich multicomponent MGs with a low Tg below 350 °C (623 K) and a wide TPF window of over 70 K, resulting in excellent thermoplastic formability (TPFA). Notably, the MGs we developed exhibit a lower Tg than advanced engineering plastics like Polyimide and Polybenzimidazole, which suggests that the TPF process of plastics could be extended to MGs. In addition, we employed Flash-DSC to accurately identify the TPF window and TPFA according to the heating rate in a wide range from 10-1 to 104 K/s, and proposed novel TPFA parameters that are based on continuous heating transformation diagram with iso-viscosity contours. Our findings demonstrate that even marginal MGs have a significant advantage in manufacturing micro-to-nano scale products that can be molded at ultra-fast heating rates, similar to advanced engineering plastics. Indeed, this work will undoubtedly inspire us to further explore the potential of MGs as a practical material for industrial applications.