The Mechanical Properties and Corrosion Resistance of Magnesium Alloys with Different Alloying Elements for Bone Repair

In order to make a rational design of magnesium alloys for bone repair, four kinds of Mg alloy ingots were prepared by vacuum induction furnace, namely Mg-3Zn-0.2Ca (wt.%) (ZX30), Mg-3Zn-0.8Zr (wt.%) (ZK30), Mg-3Zn-0.8Zr-0.3Sr (wt.%) (ZKJ300) and Mg-3Zn-0.8Zr-0.3Ca-0.3Ag (wt.%) (ZKXQ3000) alloys. The four ingots were extruded into bar materials through a hot-extrusion process under different temperatures with different extrusion ratios, the mechanical performances and the corrosion behaviors in the simulated body fluid (SBF) of the four alloys were investigated, and the mechanism of fracture and corrosion was characterized by scanning electron microscopy (SEM). The results showed the ultimate compressive strength (UCS) of all the alloys were found to be around 360 MPa, while ultimate tensile strengths (UTS) of ZKJ300 (334.61 ± 2.92 MPa) and ZKXQ3000 (337.56 ± 2.19 MPa) alloys were much higher than those of ZX30 (298.17 ± 0.93 MPa) and ZK30 (293.26 ± 2.71 MPa) alloys. The electrochemical noise and immersion tests in the SBF indicated that ZK30 alloy performed better in corrosion resistance.