Viscous flow and thermoplastic forming ability of a Zr-based bulk metallic glass composite with Ta dispersoids

The thermoplastic deformation behavior of a Zr _47.3Cu ₃₂Al ₈Ag ₈Ta ₄Si _0.7-based bulk metallic glass composite (BMGC) is studied using thermal mechanical analyzer (TMA) and high temperature compression test in the supercooled liquid (SCL) region. The deformation behavior of the Zr _47.3Cu ₃₂Al ₈Ag ₈Ta ₄Si _0.7-based BMGC rod is investigated using TMA under compression at different strain rates (5 × 10 ^-2 to 5 × 10 ^-1 s ^-1) and at different temperatures above the onset temperature of viscous-flow (∼740 to 764 K) in the SCL region. It is observed that, at a constant strain rate of 5 × 10 ^-2 s ^-1, the flow stress decreases with increasing temperature and reaches a relatively low value about 76 MPa at 764 K. In parallel, the value of flow stress increases with increasing strain rate at the same testing temperature. A satisfactory thermoplastic forming ability of the Zr _47.3Cu ₃₂Al ₈Ag ₈Ta ₄Si _0.7-based BMGC in the SCL region is demonstrated by imprinting the hologram pattern.