A thermoplastic forming map of a Zr-based bulk metallic glass

A thermoplastic forming (TPF) map of a Zr35Ti30Be26.75Cu8.25 bulk metallic glass was constructed through systematic hot-embossing experiments, spanning a wide range of strain rates and temperatures in the supercooled liquid region. By comparison with the corresponding deformation map, it is found that Newtonian flow, non-Newtonian flow and inhomogeneous flow regions correspond well to fully filled, partially filled and non-filled regions, respectively, in the hot-embossing TPF map. Furthermore, the spatio-temporally homogeneous flow facilitates the thermoplastic formabillity of the Zr-based bulk metallic glass, which is rationalized in terms of free volume theory as well as by finite element simulations. Finally, our results are corroborated by potential application tests. (c) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.