Effects of Zn on the microstructure, mechanical property and bio-corrosion property of Mg–3Ca alloys for biomedical application

The effects of the addition of Zn element on the microstructures, mechanical properties and bio-corrosion properties of Mg–3Ca alloys are investigated. The microstructure and X-ray diffraction topography indicate that as-cast Mg–3Ca alloys are composed of primary Mg and eutectic (α-Mg + Mg2Ca) phases, while Mg–3Ca–2Zn alloys are constituted of primary Mg and eutectic (α-Mg + Mg2Ca + Ca2Mg6Zn3) phases. Mechanical properties results show that the element Zn could improve both tensile strength and elongation of Mg–3Ca alloys. The ultimate tensile strength is enhanced by 22%. Meanwhile, the corrosion resistance is increased by the addition of Zn element. It is thought that the presence of Ca2Mg6Zn3 phase mainly contributes to these improvements. Mg–3Ca–2Zn alloy provides moderate strength and excellent corrosion resistance for biomedical application.