Microstructure, mechanical properties, and degradation behavior of biodegradable Zn-xMn alloys

Medical degradable zinc alloy is a new kind of biomaterial, which has attracted extensive attention because of its excellent biocompatibility and suitable degradation rate. In this study, Zn- x Mn ( x =0.2, 0.4, 0.6, 0.8, 1 wt.%) alloys were prepared by stir casting method, and their microstructure, mechanical properties and in vitro degradation properties were characterized and studied in detail. The results showed that the addition of Mn refined the grain size and significantly improved the mechanical properties of the alloy. Compared with the as-cast pure zinc, the hardness, ultimate tensile strength (UTS) and compressive yield strength (CYS) of Zn-1Mn alloy increased by 9.24 times, 5.02 times and 3.63 times, respectively. Meanwhile, the addition of Mn resulted in the formation of hard MnZn 13 phase in the alloy, which improved the wear resistance of the zinc alloy. In vitro degradation tests showed that the degradation rate of the alloy increased as the Mn addition increased, which was attributed to the formation of MnZn 13 phase, and the MnZn 13 phase promoted the galvanic corrosion of the alloy matrix. After two months of immersion, the UTS, elongation and CYS of Zn-1Mn alloy were 142.91 MPa, 2.06% and 148.62 MPa, respectively. As a new type of biodegradable implant material, Zn- x Mn alloy had great potential in the biomedical field, and this work laid a foundation for the development of Zn based biodegradable implant materials.