A comparative study on the microstructure and tensile properties of Mg-10.5Gd-2Y-0.3Zr (GW) alloys and Mg-10.5Gd-2Y-1.5Ag-0.3Zr (GWA) alloys at different temperatures was conducted. The results show that the main phases are α-Mg and Mg₅(Gd, Y) compounds in the as-cast GW alloy, and that Ag₂Gd particles are detected after Ag addition. Furthermore, grain refinement is achieved through Ag addition. After heat treatment, \(\beta^{\prime }\) precipitates are formed in the aged GW alloy, and \(\gamma^{\prime \prime \prime }\) precipitates are observed in the aged GWA alloy in addition to the \(\beta^{\prime }\) phase. Ag addition markedly improves the tensile strength at both room and elevated temperatures. The aged GWA alloy exhibits a superior strength to the GW alloy, which has an ultimate tensile strength (UTS) of 317 MPa and a tensile yield strength (YS) of 283 MPa at 250 °C, and showing a moderate strength with a UTS of 247 MPa and a YS of 205 MPa at 300 °C. The strengthening mechanism is conveniently clarified, and the excellent strength is mainly due to grain refinement, solid strengthening and abundant \(\beta^{\prime }\) and \(\gamma^{\prime \prime \prime }\) precipitates.

Graphical Abstract

中文翻译：

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添加Ag对Mg-Gd-Y-Zr合金高温力学性能的细化机制及改善

对 Mg-10.5Gd-2Y-0.3Zr (GW) 合金和 Mg-10.5Gd-2Y-1.5Ag-0.3Zr (GWA) 合金在不同温度下的显微组织和拉伸性能进行了对比研究。结果表明，铸态GW合金中的主要相为α-Mg和Mg ₅ (Gd, Y)化合物，添加Ag后检测到Ag ₂ Gd颗粒。此外，通过添加 Ag 实现晶粒细化。热处理后，在老化的 GW 合金中形成了\(\beta^{\prime }\)析出物，另外在老化的 GWA 合金中观察到了\(\gamma^{\prime \prime \prime }\)析出物到\(\beta^{\prime }\)阶段。添加 Ag 显着提高了室温和高温下的拉伸强度。时效后的 GWA 合金表现出优于 GW 合金的强度，其极限拉伸强度 (UTS) 为 317 MPa，250 °C 下的拉伸屈服强度 (YS) 为 283 MPa，显示出中等强度，UTS 为在 300 °C 时为 247 MPa 和 205 MPa 的 YS。方便地阐明了强化机制，优异的强度主要是由于晶粒细化、固体强化和大量的\(\beta^{\prime }\)和\(\gamma^{\prime \prime \prime }\)析出.

图形概要