The utilization of micro-alloying as a method to enhance the strength and ductility of Mg alloys effectively promotes their engineering applications. In this study, the addition of trace amounts of Ca/Zn elements to Mg-0.5Mn alloy significantly improved its mechanical properties, achieving a simultaneous increase in strength and ductility. The Mg-0.5Mn-0.3Zn-0.3Ca alloy exhibited optimal comprehensive mechanical properties, with a tensile yield strength (TYS) of 153 MPa, ultimate tensile strength (UTS) of 235 MPa, and fracture elongation (FE) of 30.1%. Compared to the Mg-0.5Mn alloy without Ca/Zn addition, there was a notable enhancement of 63 MPa in TYS, 71 MPa in UTS, and 19.8% in FE. In the Mg-0.5Mn-0.3Zn-0.3Ca alloy, Mn primarily exists as α-Mn elemental phase, Zn predominantly as solid solution atoms, and Ca mainly in the form of Mg₂Ca second phase and solute atom segregations. The incorporation of Zn enhances the texture intensity, contributing to texture strengthening and solid solution strengthening effects. The addition of Ca activates twinning during the extrusion process, weakening the texture through twinning-induced recrystallization. The combined effects of solid solution strengthening, segregation strengthening, and the synergistic activation of multiple slip systems by Ca/Zn elements enhance plastic deformation capability, promoting concurrent improvements in strength and ductility. The significant enhancement in overall mechanical properties achieved through the addition of trace alloying elements Ca/Zn holds promise for advancing the engineering application of this alloy and provides a case for the development of new high-performance Mg alloys.

中文翻译：

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揭示痕量 Ca/Zn 在稀释 Mg-0.5Mn 合金中弱化织构和提高强度-延展性平衡的协同作用


利用微合金化作为提高 Mg 合金强度和延展性的方法，有效地促进了其工程应用。在本研究中，在 Mg-0.5Mn 合金中添加痕量的 Ca/Zn 元素显着改善了其力学性能，同时实现了强度和延展性的提高。Mg-0.5Mn-0.3Zn-0.3Ca合金表现出最佳的综合力学性能，拉伸屈服强度（TYS）为153MPa，极限拉伸强度（UTS）为235MPa，断裂伸长率（FE）为30.1%。与未添加 Ca/Zn 的 Mg-0.5Mn 合金相比，TYS 中提高了 63MPa，UTS 中提高了 71MPa，FE 中提高了 19.8%。在 Mg-0.5Mn-0.3Zn-0.3Ca 合金中，Mn 主要以 α-Mn 元素相形式存在，Zn 主要以固溶体原子形式存在，Ca 主要以 Mg₂Ca 第二相和溶质原子偏析的形式存在。Zn 的掺入增强了质地强度，有助于质地强化和固溶强化效果。Ca 的添加在挤出过程中激活孪晶，通过孪晶诱导的再结晶削弱纹理。固溶体强化、偏析强化以及 Ca/Zn 元素协同激活多个滑移系统的综合作用增强了塑性变形能力，促进了强度和延展性的同步提高。通过添加痕量合金元素 Ca/Zn 实现了整体机械性能的显着提高，有望推进该合金的工程应用，并为开发新的高性能 Mg 合金提供了案例。