Mg-3Zn-1Al (AZ31) alloy is a popular wrought alloy, and its mechanical properties could be further enhanced by the addition of calcium (Ca). The formation of stable secondary phase (Mg,Al)₂Ca enhances the creep resistance at the expense of formability and, therefore, necessitates the establishment of safe working window(s) for producing wrought products. In this study, AZ31-3Ca alloy has been prepared by the disintegrated melt deposition (DMD) processing route, and its hot deformation mechanisms have been evaluated, and compared with similarly processed AZ31, AZ31-1Ca and AZ31-2Ca magnesium alloys. DMD processing has refined the grain size to 2–3 μm. A processing map has been developed for the temperature range 300–450 °C and strain rate range 0.0003–10 s⁻¹. Three working domains are established in which dynamic recrystallization (DRX) readily occurs, although the underlying mechanisms of DRX differ from each other. The alloy exhibits flow instability at lower temperatures and higher strain rates, which manifests as adiabatic shear bands. A comparison of the processing maps of these alloys revealed that the hot deformation mechanisms have not changed significantly by the increase of Ca addition.

中文翻译：

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分解熔体沉积（DMD）制备的AZ31-3Ca合金的热机械加工

Mg-3Zn-1Al（AZ31）合金是一种流行的锻造合金，通过添加钙（Ca）可以进一步提高其机械性能。稳定的第二相（Mg，Al）₂ Ca的形成以可成形性为代价提高了抗蠕变性，因此必须建立用于生产锻造产品的安全工作窗口。在这项研究中，通过分解熔体沉积（DMD）工艺路线制备了AZ31-3Ca合金，并评估了其热变形机理，并将其与相似处理的AZ31，AZ31-1Ca和AZ31-2Ca镁合金进行了比较。DMD处理将晶粒尺寸细化为2–3μm。已针对温度范围300–450°C和应变速率范围0.0003–10 s ^-1开发了处理图。建立了三个工作域，其中动态重结晶（DRX）容易发生，尽管DRX的基本机制彼此不同。该合金在较低的温度和较高的应变速率下表现出流动不稳定性，这表现为绝热剪切带。对这些合金的加工图进行比较发现，由于添加Ca的增加，热变形机理没有显着改变。