Abstract The microstructural evolution of as-cast, solid-solution-treated, extruded, and forged MgY12Zn2.5 magnesium alloys were observed, and the strengthening and toughening mechanisms of the deformed alloys were studied. The results showed that α-Mg solid solution was transformed into a lamellar structure of the 14H-LPSO + 2H-Mg phase, after solution treatment. The lamellar composite structure of the 14H-LPSO, 2H-Mg, and 18R-LPSO was formed by extrusion of the solid-solution-treated alloy and then a forging deformation. In the process of plastic deformation, the three-phase (2H-Mg, 14H-LPSO and 18R-LPSO) coordinated deformation and uniform distribution of the stress and strain, effectively restricting the stress concentration at the interface and delaying the initiation of cracks. The ultimate tensile stress (UTS), yielding tensile stress (YTS), and elongation of the MgY12Zn2.5 at room temperature were 415.0 MPa, 395.25 MPa, and 14.2%, respectively, reaching the level of the high-strength and high-toughness magnesium alloys.

中文翻译：

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MgY12Zn2.5镁合金的三相强韧化机制

摘要 观察了铸态、固溶处理、挤压和锻造MgY12Zn2.5镁合金的显微组织演变，研究了变形合金的强韧化机制。结果表明，固溶处理后，α-Mg固溶体转变为14H-LPSO+2H-Mg相的层状结构。14H-LPSO、2H-Mg和18R-LPSO的层状复合结构是通过固溶处理合金的挤压和锻造变形形成的。在塑性变形过程中，三相（2H-Mg、14H-LPSO和18R-LPSO）协调变形和应力应变均匀分布，有效抑制界面应力集中，延缓裂纹萌生。极限拉应力（UTS）、屈服拉应力（YTS）、