Zheng Haoran, Sun Weitao, Deng Lijun, Zhao Li, Shin Kwang Seon, Zhang Jian
Aerospace and Mechanical College, Shandong University of Aeronautics, Binzhou 256600, China.
Shandong Provincial Key Laboratory of Advanced Technology and Equipment for Laser Additive Manufacturing, Binzhou 256600, China.
Materials (Basel). 2025 Jun 1;18(11):2586. doi: 10.3390/ma18112586.
Mg alloys are highly attractive for biodegradable surgical clips because of their low density and good biocompatibility; however, their limited strength and ductility restrict their widespread application. To overcome this limitation, this study employed screw rolling (SR) to produce a Mg-3Zn-0.2Ca alloy with a fine microstructure and an average grain size of 1.6 µm. Experimental results showed that the SR process improved the comprehensive tensile properties of the alloy, increasing the yield strength, ultimate tensile strength, and elongation from 192.6, 234.4 MPa, and 21.7% for the pre-extruded alloy to 252.3, 289 MPa, and 39.5%, respectively. Quantitative analysis of the strengthening behaviour identified grain refinement as the primary strengthening mechanism, along with considerable contributions from Orowan and dislocation strengthening. The ultra-high-tensile ductility was primarily attributed to the low internal stress, nano-sized precipitates, texture weakening, and activation of multiple slip systems. These findings provide a strategy for simultaneously increasing the ductility and strength of Mg alloys and lay a foundation for applying them as biodegradable clips.
镁合金因其低密度和良好的生物相容性，对于可生物降解手术夹极具吸引力；然而，其有限的强度和延展性限制了它们的广泛应用。为克服这一限制，本研究采用螺杆轧制（SR）工艺制备了一种微观结构精细、平均晶粒尺寸为1.6 µm的Mg-3Zn-0.2Ca合金。实验结果表明，螺杆轧制工艺改善了合金的综合拉伸性能，将预挤压合金的屈服强度、极限抗拉强度和伸长率分别从192.6、234.4 MPa和21.7%提高到252.3、289 MPa和39.5%。对强化行为的定量分析确定晶粒细化是主要强化机制，同时奥罗万强化和位错强化也有相当大的贡献。超高的拉伸延展性主要归因于低内应力、纳米尺寸析出相、织构弱化以及多个滑移系的激活。这些发现为同时提高镁合金的延展性和强度提供了一种策略，并为将其应用于可生物降解夹子奠定了基础。
