In this study, the effects of Zr and Sr on the microstructure, tensile properties and in vitro biocorrosion behavior of Mg–4Zn alloy were investigated. The results show that the grain size of Mg–4Zn alloy is refined by adding Zr or Sr elements, but the tensile properties of Mg–4Zn alloy with Zr element are improved, while those with Sr element are decreased. Grains of Mg–4Zn–0.3Zr become uniform and the average grain size is 91 μm. The yield strength, tensile strength and elongation of Mg–4Zn–0.3Zr alloy are 95 ± 2.1 MPa, 188 ± 1.5 MPa and 15.00 ± 0.3%, respectively. The average grain size of Mg–4Zn–0.5Sr alloy is only 80 μm, but Mg₁₇Sr₂ phases precipitate at the grain boundary, which causes a decrease in mechanical properties. The yield strength, tensile strength and elongation of Mg–4Zn–0.5Sr alloy are 82 MPa, 161 MPa and 10.30%, respectively. After hot extrusion, the grain is obviously refined, and the broken second phases are dispersed in the matrix. The yield strength, tensile strength and elongation of as-extruded Mg–4Zn–0.5Sr alloy increase to 207 ± 3.2 MPa, 252 ± 3.0 MPa and 18.81 ± 0.3%, while the tensile properties of the as-extruded Mg–4Zn–0.3Zr alloy are slightly lower. The immersion tests and electrochemical measurements show that the corrosion resistance of the as-extruded alloys is better than that of the as-cast alloys. As-extruded Mg–4Zn–0.3Zr alloy has the best corrosion resistance, the average corrosion rate is 0.3453 ± 0.009 mm/year by the immersion test, and the current density is 9.71 μA/cm².

在这项研究中，研究了Zr和Sr对Mg-4Zn合金的显微组织，拉伸性能和体外生物腐蚀行为的影响。结果表明，通过添加Zr或Sr元素可以细化Mg–4Zn合金的晶粒尺寸，但是具有Zr元素的Mg–4Zn合金的拉伸性能得到改善，而具有Sr元素的Mg–4Zn合金的拉伸性能却下降。Mg–4Zn–0.3Zr晶粒变得均匀，平均晶粒尺寸为91μm。Mg–4Zn–0.3Zr合金的屈服强度，拉伸强度和延伸率分别为95±2.1 MPa，188±1.5 MPa和15.00±0.3％。Mg–4Zn–0.5Sr合金的平均晶粒尺寸仅为80μm，而Mg ₁₇ Sr ₂相在晶界析出，导致机械性能下降。Mg-4Zn-0.5Sr合金的屈服强度，拉伸强度和伸长率分别为82 MPa，161 MPa和10.30％。热挤压后，晶粒明显细化，破碎的第二相分散在基体中。挤压后的Mg-4Zn-0.5Sr合金的屈服强度，拉伸强度和伸长率分别提高到207±3.2 MPa，252±3.0 MPa和18.81±0.3％，而拉伸后的Mg–4Zn–0.3合金的拉伸性能Zr合金略低。浸没测试和电化学测量表明，挤压态合金的耐蚀性优于铸造态合金。挤压成型的Mg–4Zn–0.3Zr合金具有最佳的耐腐蚀性，通过浸没测试，平均腐蚀速率为0.3453±0.009 mm /年，²。