(1. 青海大學 青海省高性能輕金屬合金及深加工工程技術(shù)研究中心，西寧 810016；
2. 青海大學 青海省新型輕合金重點實驗室，西寧 810016)
摘 要: 通過重力鑄造法制備不同成分的AE44-2合金以及熱擠壓成型，研究La、Ce含量對擠壓態(tài)AE44-2鎂合金的組織、織構(gòu)和力學性能的影響。結(jié)果表明：擠壓過程中AE44-2鎂合金破碎的Al-RE相，可以提供大量異質(zhì)形核點，促進晶粒進行動態(tài)再結(jié)晶，形成細小晶粒，有利于弱化織構(gòu)強度和提高力學性能。由于La、Ce添加量不同，4種擠壓態(tài)AE44-2鎂合金平均晶粒尺寸為3.7 μm左右，富Ce擠壓態(tài)AE44-2鎂合金的再結(jié)晶程度比富La的更完全，富Ce弱化擠壓態(tài)AE44-2鎂合金的織構(gòu)效果比富La弱化擠壓態(tài)AE44-2鎂合金的強。4種合金中，Mg-4Al-1.5La-2.5Ce-0.3Mn合金的再結(jié)晶程度較完全，織構(gòu)強度小，平均晶粒細小至3.2 μm且Al-RE相分布均勻，綜合力學性能最好。
關(guān)鍵字: AE44-2鎂合金；熱擠壓；再結(jié)晶；織構(gòu)；力學性能
（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
