新型α+β双基体相Mg-9Li-3Al-2.5Sr合金的微观组织与力学性能研究（英文）  

Microstructure and Mechanical Behavior of a New α+β-Type Mg-9Li-3Al-2.5Sr Alloy

作　　者：杨艳[1] 彭晓东[1] 谢卫东[1] 魏国兵[1] 许峰[1] 魏群义[1] 

机构地区：[1]重庆大学,重庆400044

出　　处：《稀有金属材料与工程》2014年第6期1281-1285,共5页Rare Metal Materials and Engineering

基　　金：National Basic Research Program of China(2007CB613702);International Scientific and Technological Cooperation Projects(2010DFR50010)

摘　　要：采用传统铸造方法分别制备了Φ10 mm和Φ90 mm Mg-9Li-3Al-2.5Sr(LAJ932)合金锭。在挤压温度260℃,挤压比28条件下对Φ90 mm合金锭进行挤压。分别分析和报道了铸态和挤压态LAJ932镁合金的微观组织和力学性能。探讨了该合金在挤压过程中的组织演变规律。研究结果表明:铸态和挤压态LAJ932镁合金均包括α-Mg(hcp)相,β-Li(bcc)相和Al4Sr相。Φ10 mm铸锭的组织比Φ90 mm铸锭组织细小得多。挤压过程中α-Mg相发生连续动态再结晶,而β-Li相发生非连续动态再结晶。挤压过程中,在hcpα-Mg相中形成{10 1 0}<10 1 0>织构,而bccβ-Li相中则形成{110}<101>织构。挤压过程中,LAJ932镁合金的强度和塑性均得到改善。挤压态Mg-9Li-3Al-2.5Sr(LAJ932)合金的抗拉强度达到235 MPa,屈服强度为221 MPa,延伸率为19.4%,合金展现出良好的力学性能。The as-cast Mg-9Li-3Al-2.5Sr （LAJ932） alloy ingots with diameters of 10 mm and 90 mm were prepared. The extrusion of Ф90 mm as-cast LAJ932 alloy ingot was carried out at 533 K with an extrusion ratio of 28. The microstructure and the mechanical properties of the as-cast and extruded LAJ932 alloys were discussed. The microstructure evolution during extrusion was analyzed. The results show that both the as-cast and the extruded LAJ932 alloys contain hcp α-Mg, bcc β-Li and A14Sr phase. The grain size of as-cast Ф10 mm specimen is smaller than that of Ф90 nun specimen. The microstructure evolution during extrusion is governed by continuous dynamic recrystallization （CDRX） in a-Mg phase whereas discontinuous dynamic recrystallization （DDRX） occurs in β-Li phase. { 1010}〈101^-0〉 texture is formed in the hcp α-Mg phase whereas { 110}〈101〉 texture is formed in the bcc β-Li phase during the extrusion process. Both the strength and the ductility of the LAJ932 alloy is improved by extrusion. The extruded LAJ932 alloy shows a favorable combination of the strength and the ductility with the tensile strength of 235 MPa, yield strength of 221 MPa and the elongation of 19.4%.

关 键 词：镁锂合金 挤压 微观组织 织构 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]