挤压温度对AZT802镁合金组织和性能的影响  

Effects of Extrusion Temperature on Microstructure and Mechanical Properties of AZT802 Magnesium Alloy

作　　者：范晓伟 张丁非[1,2] 冯靖凯 蒋璐瑶 胥钧耀[1,2] 潘复生[2,3] 

机构地区：[1]重庆大学材料科学与工程学院,重庆400045 [2]重庆大学国家镁合金材料工程技术研究中心,重庆400044 [3]重庆市科学技术研究院,重庆401123

出　　处：《材料导报》2017年第22期95-99,106,共6页Materials Reports

基　　金：国家973重大基础研究项目(2013CB632200);国家自然科学基金面上项目(51571040);国家自然科学基金重点项目(51531002);国家重点研发计划项目(2016YFB0301101)

摘　　要：将铸态AZT802合金分别在350℃、380℃和400℃下挤压,随后进行T5时效处理,研究不同挤压温度对AZT802镁合金挤压态和时效态组织和性能的影响。结果表明,当挤压温度为350℃时,晶粒尺寸分布不均匀,同时观察到大块的条状第二相沿挤压方向析出。当挤压温度高于350℃时,挤压态合金获得均匀等轴晶粒,第二相以颗粒状形貌沿晶界均匀分布。经T5时效处理后,颗粒状Mg_2Sn相均匀分布于基体中,Mg_(17)Al_(12)相以连续相和非连续相析出,非连续析出相随时效前挤压温度的升高而逐渐增多。力学性能测试结果表明,AZT802合金在380℃下挤压,并进行175℃(3h)T5时效处理后,获得最佳综合力学性能。Extrusion of as-cast AZT802 alloy was performed in the temperature of 350 ℃,380 ℃ and 400 ℃,and then the extruded alloys were given T5 aging treatment.The effects of extrusion temperature on microstructure and mechanical properties of extruded and aged AZT802 alloy were investigated.It was found that fine equiaxed grains were obtained in alloys extruded at higher extrusion temperature.With the extrusion temperature decreasing to 350 ℃,the distribution of grain size was nonuniform.The volumes of the second phases decrease with the extrusion temperature increasing.Moreover,the particle second phases distribute along the grain boundaries homogeneously at higher extrusion temperature.While large band-shaped precipitation was observed in the alloy extruded at 350 ℃.After T5 aging treatment,Mg2 Sn particles distribute homogeneously.Both continuous and discontinuous Mg_（17）Al_（12） phases were observed.The volume fraction of discontinuous Mg_（17）Al_（12）phase increased with the extrusion temperature rising.The AZT802 alloy extruded at 380 ℃ and aged at 175 ℃for 3 hpossessed the best mechanical properties.

关 键 词：镁合金 挤压温度 显微组织 力学性能 

分 类 号：TG376.2[金属学及工艺—金属压力加工]