The microstructure, texture and mechanical properties of a series of Mg–Zn–Ca–Mn alloys with three Zn/Ca ratios (2.63, 1.22 and 0.53, by weight ratio) were investigated. The dominant second phase changed from MgZn to Ca 2 Mg 6 Zn 3 as the Zn/Ca ratio decreased from 2.63 to 1.22. With decreasing Zn/Ca ratio, the grain size of the as-cast alloys was significantly decreased, accompanied by an increase in the volume fraction of second phase. For as-extruded Mg–1.4Zn–2.6Ca–0.5Mn, the finest (~ 0.36 μm) recrystallized grain structures, containing both fine MgZn 2 precipitates and α-Mn particles, were obtained at an extrusion speed of 0.01 mm/s. The texture of the deformed structure was more intense (~ 30.39 mud) relative to the recrystallized region (~ 8.33 mud). As the Zn/Ca ratio decreased, basal plane texture was weakened deriving from grain refinement following recrystallization. Superior mechanical properties with a yield strength of ~ 387.8 MPa and ultimate tensile strength of ~ 409.2 MPa were achieved in the Mg–1.4Zn–2.6Ca–0.5Mn alloy extruded at 270 °C at an extrusion speed of 0.01 mm/s. A number of factors were determined to contribute to strengthening including Hall–Petch effects from the fine recrystallized grains (contribution ~ 58.7%), dislocation strengthening of the deformed region (contribution ~ 29.3%) and Orowan strengthening (contribution ~ 12%).

中文翻译：

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Zn/Ca比对具有优异强度的稀Mg-Zn-Ca-Mn合金的显微组织、织构和力学性能的影响

研究了具有三种 Zn/Ca 比（2.63、1.22 和 0.53，按重量比）的一系列 Mg-Zn-Ca-Mn 合金的显微组织、织构和机械性能。随着 Zn/Ca 比从 2.63 降低到 1.22，主要的第二相从 MgZn 变为 Ca 2 Mg 6 Zn 3。随着 Zn/Ca 比的降低，铸态合金的晶粒尺寸显着减小，伴随着第二相体积分数的增加。对于挤压态的 Mg–1.4Zn–2.6Ca–0.5Mn，以 0.01 mm/s 的挤压速度获得了最细（~0.36 μm）的再结晶晶粒结构，其中包含细小的 MgZn 2 沉淀物和 α-Mn 颗粒。相对于再结晶区域（~ 8.33 泥），变形结构的质地更强烈（~ 30.39 泥）。随着 Zn/Ca 比值的降低，由于再结晶后晶粒细化，基面织构减弱。Mg-1.4Zn-2.6Ca-0.5Mn 合金在 270°C 下以 0.01 毫米/秒的挤压速度挤压，获得了优异的机械性能，屈服强度为~387.8 MPa，极限拉伸强度为~409.2 MPa。许多因素被确定有助于强化，包括来自细小再结晶晶粒的霍尔-佩奇效应（贡献 ~ 58.7%）、变形区域的位错强化（贡献 ~ 29.3%）和 Orowan 强化（贡献 ~ 12%）。