Synthesis of Plastic Mg-Based Bulk-Metallic-Glass Matrix Composites by Bridgman Solidification

The microstructures of the in-situ Mg-based bulk-metallic-glass (BMG) matrix composites synthesized by the copper-mold casting are inhomogeneous, and the optimized mechanical properties are usually realized through alloy composition design. In this article, Mg-based BMG matrix composites containing uniform flake-shaped precipitates with a fixed composition of Mg₇₀Cu_8.33Ni_8.33Gd_8.33Zn₅ were synthesized by the Bridgman solidification. Adjusting the withdrawal velocities controlled the size and volume fractions of the precipitates in the composites, and large plasticity was obtained by controlling the cooling condition only. Thus, the Bridgman solidification is an effective way not only to fabricate the homogeneous BMG matrix composites but also to tailor and optimize their mechanical properties.