Low-cost, soluble, and highly ductile Mg–Bi–Ca alloy prepared by extrusion and annealing

Abstract

This study investigates the formation of a high-potential Mg2Bi2Ca phase in MgBixCa2.5x (x = 0.15, 0.22, 0.37 at.%). The rate of degradation can be increased by exploiting the electrochemical corrosion formed between this phase and the magnesium matrix, while the presence of this phase also improves the dynamic recrystallization process of the alloy during extrusion-induced deformation, thereby enhancing its plasticity. The MgBi0.15Ca0.37 alloy exhibited the best comprehensive mechanical properties after annealing, with a yield strength and a tensile strength of 170 MPa and 225 MPa, respectively, and an elongation of 32.9%. Moreover, it recorded a higher increase in the rate of degradation, 150%, at 25 °C than the extruded state. We also investigated the mechanism of influence of the content, distribution, and morphology of the Mg2Bi2Ca phase in the alloy on its mechanical and degradation-related properties. The work here provides insights into the development of highly ductile and low-cost candidate materials for fracturing tools.