Mg含量对可降解Zn-Ag-Mg合金的微观组织、力学性能、耐蚀性及细胞毒性的影响

制备了不同Mg含量的铸态Zn-5Ag-xMg(x=0,0.5,1,1.5,质量分数/%)合金。采用X射线衍射仪、光学显微镜、扫描电子显微镜、万能试验机、维氏硬度计、电化学工作站和CCK-8（Cell Counting Kit-8 试剂）等,研究了Mg含量对合金的显微组织、力学性能、耐蚀性能和细胞毒性的影响。结果表明,Zn-5Ag合金的第二相为ε-AgZn₃,而Mg的加入细化了合金的晶粒并新生成了Mg₂Zn₁₁相。随着Mg含量的增加,合金的抗压屈服强度从218 MPa提高到309 MPa,维氏硬度从71.4提高到131.9。电化学测试和体外浸泡实验表明,由于Mg含量的增加导致合金的耐蚀性能下降,体外降解速率由0.08 mm/a提高到0.16 mm/a。细胞毒性结果表明,Mg的添加可以提高小鼠胚胎成骨细胞（mouse embryonic osteoblasts cells,MC3T3-E1）的活力,所有合金表现出良好的生物相容性。

Effect of Mg content on the microstructure, mechanical properties, corrosion resistance, and cytotoxicity of degradable Zn-Ag-Mg alloys

As-cast Zn-5Ag-xMg(x = 0, 0.5, 1, 1.5, mass fraction/%) alloys with different magnesium contents were prepared. The effect of Mg content on the microstructure, mechanical properties, corrosion resistance, and cytotoxicity of the alloys were investigated by X-ray diffractometer, optical microscope, scanning electron microscope, universal testing machine, Vickers hardness tester, electrochemical workstation, and cell counting Kit-8. The results show that the second phase in the Zn-5Ag alloy is ε-AgZn₃, and the addition of Mg refines the grain size of the alloy, and generates the Mg₂Zn₁₁ phase. With the increase of Mg content, the compressive yield strength of the alloy increases from 218 MPa to 309 MPa, and Vickers hardness increases from 71.4 to 131.9. Electrochemical testing and in vitro immersion experiments suggest that the increase of Mg content leads to the decrease of corrosion resistance, the in vitro degradation rate increases from 0.08 mm/a to 0.16 mm/a. Cytotoxicity results indicate that the addition of Mg enhance the viability of mouse embryonic osteoblasts cells (MC3T3-E1), indicating that all the alloys show good biocompatibility.