Abstract

Deformation behavior of a rolled Mg–Y–Nd–Gd magnesium alloy was studied at a temperature range of 240–480 °C under plane strain compression. Two types of samples including different loading-constraining configurations were employed to study anisotropy in deformation response. The result showed that plane strain deformation mode extends the temperature range for predominance of twinning up to 480 °C. However, yield anisotropy was diminished by increasing temperature to 480 °C. Moreover, plane strain deformation mode caused the development of dynamic recrystallization to be postponed to high strains. Deformation behavior of the two sample types were explained by calculation of Schmid factor and texture analysis. Fine dynamically recrystallized grains were traced to form at 420 and 480 °C. Relying on EBSD analysis, the development of new grains was explained using continuous dynamic recrystallization mechanism, where pyramidal and prismatic poles of new grains were rotated relative to their parent grain. The dynamic evolution of metastable β′ and β″ phases was also observed at high temperatures, the fraction of which was remarkably increased with increasing temperature to 420 and 480 °C.

Graphic Abstract

中文翻译：

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Mg-Y-Nd-Gd-Zr合金平面应变压缩变形机理及第二相粒子演化

摘要

研究了轧制 Mg-Y-Nd-Gd 镁合金在 240-480 °C 温度范围内在平面应变压缩下的变形行为。使用包括不同载荷约束配置的两种类型的样品来研究变形响应的各向异性。结果表明，平面应变变形模式将孪晶优势的温度范围扩展到 480 °C。然而，将温度升高到 480 °C 会降低产率各向异性。此外，平面应变变形模式导致动态再结晶的发展被推迟到高应变。两种样品类型的变形行为通过施密德因子的计算和质地分析来解释。细小的动态再结晶晶粒在 420 和 480 °C 下形成。依托EBSD分析，使用连续动态再结晶机制来解释新晶粒的发展，其中新晶粒的金字塔形和棱柱形极相对于其母体晶粒旋转。在高温下也观察到亚稳态 β' 和 β'' 相的动态演变，随着温度升高到 420 和 480°C，其比例显着增加。

图形摘要