(1. 青海大学 青海省高性能轻金属合金及深加工工程技术研究中心，西宁 810016；
2. 青海大学 青海省新型轻合金重点实验室，西宁 810016)
摘 要: 通过重力铸造法制备不同成分的AE44-2合金以及热挤压成型，研究La、Ce含量对挤压态AE44-2镁合金的组织、织构和力学性能的影响。结果表明：挤压过程中AE44-2镁合金破碎的Al-RE相，可以提供大量异质形核点，促进晶粒进行动态再结晶，形成细小晶粒，有利于弱化织构强度和提高力学性能。由于La、Ce添加量不同，4种挤压态AE44-2镁合金平均晶粒尺寸为3.7 μm左右，富Ce挤压态AE44-2镁合金的再结晶程度比富La的更完全，富Ce弱化挤压态AE44-2镁合金的织构效果比富La弱化挤压态AE44-2镁合金的强。4种合金中，Mg-4Al-1.5La-2.5Ce-0.3Mn合金的再结晶程度较完全，织构强度小，平均晶粒细小至3.2 μm且Al-RE相分布均匀，综合力学性能最好。
关键字: AE44-2镁合金；热挤压；再结晶；织构；力学性能
（1. Qinghai Provincial Engineering Research Center of High-Performance Light Metal Alloys and Forming, Qinghai University, Xining 810016, China;
2. Qinghai Province Key Laboratory of New Light Alloys, Qinghai University, Xining 810016, China）
Abstract:The different compositions of extruded AE44-2 alloy were prepared by gravity casting and hot extrusion forming. The effects of La and Ce contents on the microstructure, recrystallization, texture and mechanical properties of extruded AE44-2 magnesium alloy were investigated. The results show that the Al-RE phase of the AE44-2 magnesium alloy is fragmented to provide a large amount of heterogeneous nucleation point and promote dynamic recrystallization during the extrusion process, which makes the alloy grain refinement. Both of them promote the weakening of texture and improve the mechanical properties. Due to the different contents of La and Ce, the average grain size of the four kinds of extruded AE44-2 magnesium alloys is about 3.7 μm, and the texture effect of Ce-rich extruded AE44-2 magnesium alloy is stronger than that of La-rich one, and the degree of recrystallization of Ce-rich extruded AE44-2 magnesium alloy is more complete than that of La-rich one. Among them, the recrystallization of Mg-4Al-1.5La-2.5Ce-0.3Mn alloy is more complete and the texture strength is low, the average grain size is fined to 3.2 μm and the Al-RE phase distributes homogeneously, and the comprehensive mechanical properties are the best.
Key words: AE44-2 magnesium alloy; hot extrusion; recrystallization; texture; mechanical properties
