The Mg alloys with combination of high strength and excellent irradiation resistance are currently required for research reactors. In this work, the novel Mg-3Mn-0.5Ca alloy with a high strength of over 300 MPa has been fabricated via co-addition of Mn and Ca elements. Moreover, the Xe ion implantation (300 °C/4.5 × 1015 ions/cm2) is conducted for pure Mg, Mg-3Mn and Mg-3Mn-0.5Ca alloys. Microstructure characterization shows that the number density of dislocation loops is comparable between Mg-3Mn and pure Mg, while the phase boundary of nano-Mn particles could act as the sink to absorb more Xe atoms, resulting in the abundant formation of Xe bubbles in the matrix of irradiated Mg-3Mn alloy. With further minor addition of Ca element, the formation of Xe bubbles and dislocation loops in Mg-3Mn-0.5Ca alloy has been obviously suppressed, and the abundant grain boundaries (GBs) due to grain refinement then act as the sink region for Xe precipitation. The limited number density of Xe bubbles leads to the extremely low swelling ratio in Mg-3Mn-0.5Ca alloy, ∼0.08 %. The result above suggests that the Mn and Ca co-addition could enhance the mechanical properties and irradiation tolerance of Mg alloys, simultaneously. The present low-alloying strategy would provide a new design reference for novel nuclear materials.

中文翻译：

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通过共添加 Mn 和 Ca 元素来提高 Mg 合金的强度和耐辐照性


目前，研究反应器需要兼具高强度和出色抗辐照性的 Mg 合金。在这项工作中，通过锰和钯元素的共添加制备了强度超过 300 MPa 的新型 Mg-3Mn-0.5Ca 合金。此外，对纯 Mg、Mg-3Mn 和 Mg-3Mn-0.5Ca 合金进行了氙离子注入 （300 °C/4.5 × 1015 个离子/cm2）。微观结构表征表明，Mg-3Mn 和纯 Mg 的位错环数密度相当，而纳米 Mn 颗粒的相界可以作为吸收更多 Xe 原子的汇，从而在辐照 Mg-3Mn 合金的基体中形成大量 Xe 气泡。随着Ca元素的进一步少量添加，Mg-3Mn-0.5Ca合金中Xe气泡和位错环的形成得到了明显的抑制，晶粒细化引起的丰富晶界（GBs）成为Xe沉淀的汇区。Xe 气泡的有限数量密度导致 Mg-3Mn-0.5Ca 合金的膨胀率极低，约为 0.08 %。以上结果表明，Mn 和 Ca 的共加成可以同时提高 Mg 合金的力学性能和耐辐照性。目前的低合金化策略将为新型核材料提供新的设计参考。