A new type of Mg-Zn-Y-Nd alloy for degradable orthopedic implants was developed. In the present study, the Zn and Y content was adjusted and their influences on the microstructures and mechanical behaviors were discussed in depth. The results showed that the as-extruded Mg-Zn-Y-Nd alloys are mainly composed of fine dynamic recrystallized grains (DRXed grains), large unDRXed grains and linearly distributed secondary phases. The change of Zn content exerts little influence on the grain structure of the extruded Mg-Zn-Y-Nd alloy, while the increase of Y content would hinder the dynamic recrystallization process and the growth of the DRXed grains, thus the size and volume fraction of the equiaxed DRXed grains decrease. The tensile and compressive properties are very little affected by Zn content because of the similar grain structure. As Y content increases, the tensile yield strength (TYS) and ultimate strength (TUS) increase while the elongation decreases, this is caused by a combined strengthening effect of grain refinement, texture, precipitation and twinning. The compressive yield strength (CYS) and ultimate strength (CUS) of Mg-Zn-Y-Nd alloy with different Y content exhibit a similar tendency as the tensile test.

开发了一种新型的可降解骨科植入物Mg-Zn-Y-Nd合金。在本研究中，调整了Zn和Y的含量，并深入讨论了它们对微观结构和力学行为的影响。结果表明，挤压态的Mg-Zn-Y-Nd合金主要由动态细晶粒（DRXed晶粒），大的未DRX晶粒和线性分布的第二相组成。Zn含量的变化对挤压Mg-Zn-Y-Nd合金的晶粒结构影响很小，而Y含量的增加会阻碍动态再结晶过程和DRXRX晶粒的生长，从而影响其尺寸和体积分数等轴DRXd晶粒的减小。由于相似的晶粒结构，拉伸和压缩性能几乎不受锌含量的影响。随着Y含量的增加，抗拉屈服强度（TYS）和极限强度（TUS）升高，而伸长率降低，这是由于晶粒细化，织构，析出和孪晶的综合强化作用引起的。Y含量不同的Mg-Zn-Y-Nd合金的压缩屈服强度（CYS）和极限强度（CUS）表现出与拉伸试验相似的趋势。