Flow characteristics and formability of a bulk metallic glass with a wide undercooled liquid region

Abstract

Deformation behavior of Zr44Ti11Cu9.8Ni10.2Be25 (number indicate at.%) bulk metallic glass having a wide undercooled liquid temperature interval has been investigated by performing a series of compression tests after rapid heating. The regions of brittle fracture, a non-Newtonian flow, and a Newtonian viscous flow were identified depending on the test conditions in terms of initial strain rate and temperature. A deformation map was constructed by applying both transition state and Newtonian viscous equations to the flow stress data to provide the boundaries between these three different deformation modes. The basic processing map based on a dynamic materials model has also been constructed to obtain an optimal forming condition. (c) 2006 Elsevier B.V. All rights reserved.