Mg-Sm系合金的显微组织及力学性能  

Microstructure and mechanical properties of Mg-Sm alloys

作　　者：朱蓓蓓[1,2] 孙扬善[1,2] 贾迪[1,2] 薛烽[1,2] 

机构地区：[1]东南大学材料科学与工程学院,南京211189 [2]东南大学江苏省先进金属材料高技术研究重点实验室,南京211189

出　　处：《东南大学学报（自然科学版）》2009年第3期610-614,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家科技支撑计划资助项目(2006BAE04B07)

摘　　要：研究了Mg-(1%～3%)Sm(质量分数)合金在多种状态下的显微组织和力学性能.采用光学金相分析(OM),扫描电子显微分析(SEM),X射线衍射分析(XRD)等多种分析和测试手段,系统研究了挤压工艺及热处理(固溶处理、时效处理)对Mg-Sm系合金显微组织和力学性能的影响.结果显示,合金的铸态组织由α-Mg基体和Mg41Sm5组成.合金经热挤压加工后,Mg41Sm5相沿挤压方向呈纤维或颗粒状分布.在420℃挤压时,试样内发生了动态再结晶,致使挤压后合金的强度和塑性得到大幅度改善.固溶以及时效处理后,合金的性能比铸态有较大提高;而采用挤压后的直接时效(T5)处理,可获得良好的综合力学性能.因此,Sm可以考虑作为强化变形镁合金的添加元素.Three binary Mg- （ 1% to 3 % ） Sm alloys were prepared and their microstructure and mechanical properties were investigated. The effects of extrusion and heat treatment on the microstructure and mechanical properties of Mg-Sm binary alloys were investigated by using an optical microscope （OM）, a scanning electron microscope （SEM）, and an X-ray diffract meter （XRD）. The results show that the microstructure of the alloys prepared as-cast consists of an a-Mg matrix and Mg41 Sm5 intermetallic compound. After the hot-extrusion, the Mg41 Sm5 phase shows fibrous and granular morphology along the extrusion direction. Dynamic recrystallization occurs during extrusion at 420℃, resuiting in a remarkable increase in both strength and ductility of the alloys. After the solution and aging treatment, the mechanical properties of the alloys are much higher than those under as-cast conditions and optimum properties are obtained from the specimens aged directly after extrusion. As a resuit, Sm can be considered as an additive element to make wrought magnesium alloys stronger.

关 键 词：镁 钐 合金 挤压 时效 脱溶 

分 类 号：TG146.22[一般工业技术—材料科学与工程]