C18150合金搅拌摩擦焊焊缝微观组织与力学性能分析  

Microstructure and mechanical characterization of a friction-stir-welded C18150 butt joint

作　　者：贺地求 薛飞[2] 孙友庆 HE Diqiu;XUE Fei;SUN Youqing(College of Light Alloy Research,Central South University,Changsha 410083,China;State Key Laboratory of High Performance Complex Manufacturing,Central South University,Changsha 410083,China)

机构地区：[1]中南大学轻合金研究院,长沙410083 [2]中南大学高性能复杂制造国家重点实验室,长沙410083

出　　处：《焊接学报》2019年第11期93-99,I0005,共8页Transactions of The China Welding Institution

基　　金：国家重点基础研究发展规划(973计划)项目(2014CB046605);中南大学研究生自主探索创新项目(2018zzts484)

摘　　要：采用搅拌摩擦焊的方法对铬锆铜合金(Cu-Cr-Zr合金)进行了焊接,采用金相显微镜、场发射扫描电镜、背散射电子衍射仪对焊缝的微观组织性能进行了研究,采用拉伸试验和硬度试验对焊缝的力学性能进行了分析.结果表明,铬锆铜焊核区的最终晶粒状态表现为动态再结晶晶粒和部分动态回复晶粒的组合,其动态再结晶机制为连续动态再结晶机制.铬锆铜焊核区可以发现直径约为5~10μm的粗大颗粒,通过EDS分析发现其成分主要为Cr元素.焊核区的纳米沉淀强化相由于较高的焊接温度和热循环全部回溶到铜基体中,纳米沉淀强化相的回溶导致焊缝的抗拉强度和硬度都比母材区有所降低.In this study, the Cu-Cr-Zr alloy was welded by means of friction stir welding. Particularly, the microstructure of joints was observed by Metalloscope, SEM and Electron backscatter diffraction(EBSD). The mechanicalproperties were investigated by tension test and micro-hardness test. The result shows that the final grain structure in the nugget zone is composed of grains in state of dynamic recrystallization and partial dynamic recovery. The dynamic recrystallization process is a continuous dynamic recrystallization process. Coarse particles which are 5 ~ 10 μm in length are found innugget zone of Cu-Cr-Zr. The EDS analysis further reveals that these coarse particles are mainly composed of Cr element. All these precipitates are dissolved due to the high temperature in the nugget zone of Cu-Cr-Zr. The microhardness and tensile strength of nugget zone decreased due to the dissolution of precipitates.

关 键 词：铬锆铜合金 粗大颗粒 Cr沉淀强化相 抗拉强度 硬度 

分 类 号：TG453.9[金属学及工艺—焊接]