Assessment of Microstructure and Mechanical Properties of As-cast Magnesium Alloys Reinforced with Organically Extracted Zinc and Calcium

Magnesium (Mg) is commonly used as a biomaterial because of its biocompatibility, biodegradation, non-toxicity, and good mechanical properties. The conventional consideration for selecting Mg alloy elements is based on their corrosion resistance, good hardness, and strength. Therefore, some of the alloying elements that enable the above properties are zinc, calcium, and aluminum. The future requirement of biomaterial involves non-toxicity in addition to the existing properties. The tensile strength and hardness of polymeric materials used as a replacement for metallic materials in biomedical applications were lesser. Therefore, calcium and zinc were sourced organically from cow bones and cocoa seeds, respectively, to eliminate the adverse effect of the inorganic source of the same element. Zinc and calcium were alloyed with magnesium at different percentages recommended by Junjin, 2017 experiments (0.23% Zn, 0.15% Ca in alloy 1 and 0.25% Zn, 0.23% Ca in alloy 2). The hardness, tensile strength, and percentage elongation of the as-cast materials from organic alloy sources were investigated and compared to similar experiments from the literature with the inorganic alloy source. The result showed that Mg alloy with organic zinc and calcium exhibit better hardness (52.1 HRv in alloy 1 and 60.7 HRv in alloy 2), tensile strength (181.3 MPa in alloy 1 and 208.3MPa in alloy 2), and ductility (13.1% elongation in alloy 1 and 18% in alloy 2) compared to Jinjin Mg alloy from an inorganic source of lesser values of mechanical properties. It can be concluded that zinc and calcium from organic sources is a better replacement for inorganic sources in Mg alloy.