The synergic strengthening of multiple phases is an essential way to achieve high-performance Mg alloys. Herein, Mg-Gd-Zn alloy containing four phases was prepared by rapid solidification (RS) ribbons and spark plasma sintering (SPS). The microstructure of the alloy consisted of α-Mg, nanosized β₁ phase particles, lamellar long period stacking ordered (LPSO) phase, and β′ phase precipitates. The microstructural evolution was also investigated. The results show that the metastable β₁ phase was formed in the as-cast solidification through rapid solidification, because both Zn atoms and the short holding-time at molten liquid facilitated the formation of the β₁ phase. The β₁ phase grew from 35.6 to 154 nm during the sintering process. Meanwhile, the fine lamellar LPSO phase was simultaneously formed after the Zn-Gd clusters were generated from the supersaturated solid solution, and the width of the LPSO phase was only in the range of 2–30 nm. The third strengthening phase, the metastable β′ phase, was obtained by aging treatment. The results of hardness testing implied that the hardness of the alloy containing the aforementioned three nanosized strengthening phases significantly improved about 47% to 126 HV compared with that of the as-cast ingot.

中文翻译：

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火花等离子体烧结法制备多相Mg96.9Gd2.7Zn0.4合金的组织演变

多相协同强化是获得高性能镁合金的重要途径。在此，通过快速凝固（RS）薄带和火花等离子体烧结（SPS）制备包含四相的Mg-Gd-Zn合金。该合金的微观结构由α-Mg系，纳米β的_1米相的颗粒，层状长周期叠层（LPSO）相，β'相沉淀物。还研究了微观结构的演变。结果表明，亚稳β ₁形成在通过快速凝固铸态凝固阶段，因为这两个锌原子和熔融液体的短保持时间促进了β的形成₁相。该β ₁在烧结过程中，相从35.6nm增加到154nm。同时，从过饱和固溶体生成Zn-Gd团簇后，同时形成了细小片状LPSO相，LPSO相的宽度仅在2-30 nm范围内。通过时效处理获得第三强化相，亚稳β′相。硬度测试的结果表明，与铸锭相比，包含上述三个纳米级强化相的合金的硬度显着提高了约47％至126 HV。