Thermoplastic forming ability of a Mg-base bulk metallic glass composites reinforced with porous Mo particles

The thermoplastic deformation behavior of the Mg₅₈Cu _28.5Gd₁₁Ag_2.5 metallic glass composites (BMGCs) reinforced with porous Mo particles was studied by means of thermal scanning calorimetry (DSC), thermal mechanical analysis (TMA) and high-temperature compression test in the supercooled liquid region. Based on the result obtained from DSC and TMA, the deformation behavior for Mg₅₈Cu _28.5Gd₁₁Ag_2.5 BMGC rod was investigated by compression test at different strain rates (1 × 10^-2-1 × 10^-1 s^-1) and temperatures in the supercooled liquid region, namely 433 K, 438 K, and 443 K. The flow stresses obtained at a constant strain rate of 1 × 10^-2 s^-1 decrease with increasing temperature and reach a low stress about 10 MPa at 443 K. In addition, the X-ray diffraction results confirm that the Mg₅₈Cu _28.5Gd₁₁Ag_2.5 BMGC samples remain the amorphous nature after compression at 443 K. The current results indicate that the Mg₅₈Cu_28.5Gd₁₁Ag_2.5 BMGC possesses an excellent superplastic formability with the m-value (strain rate sensitivity) greater than 0.7 in the supercooled liquid region of 438-443 K at a strain rate around 1 × 10^-2 s^-1.