2219-T87超声辅助搅拌摩擦焊接头组织与性能  

Research on the Microstructure and Mechanical Properties of Ultrasonic Assisted Friction Stir Welding Joints of 2219-T87Aluminum Alloy

作　　者：贺地求[1] 赵志峰 赖瑞林[1] 杨坤玉[1] HE Diqiu;ZHAO Zhifeng;LAI Ruilin;YANG Kunyu(State Key Laboratory of High Performance and Complex Manufacturing,Central South University,Changsha 410083,China)

机构地区：[1]中南大学高性能复杂制造国家重点实验室,湖南长沙410083

出　　处：《湖南大学学报（自然科学版）》2018年第4期41-47,共7页Journal of Hunan University:Natural Sciences

基　　金：国家重点基础研究发展规划(973计划)项目(2014CB046605)~~

摘　　要：为了研究超声辅助对2219铝合金搅拌摩擦焊接头组织与性能的影响,采用超声辅助搅拌摩擦焊方法对3mm厚2219-T87铝合金板进行对接焊试验.对接头进行微观组织分析、力学性能测试、三维应变测试、断口扫描及XRD实验分析.结果表明,在搅拌摩擦焊接过程中加入高频超声振动,焊缝抗拉强度提高了8.48%,断裂应变提高了9.25%,同时有效改善了焊接接头微观组织的上下不均匀性,增大了焊缝底部横截面尺寸,对焊缝底部缺陷有明显的抑制作用,且通过XRD试验,发现在搅拌摩擦焊过程加入超声后,由于焊接温度的下降,使得强化相θ″相与θ′相长大聚集程度下降,同时粗大的θ相粒子聚集程度降低,使焊缝综合力学性能得到提高.In order to investigate the effect of ultrasonic assistance on the microstructure and properties of 2219 aluminum alloy welded joint,the butt welding test on 3 mm thickness 2219-T87 aluminum alloy plate was carried out by ultrasonic assisted friction stir welding method.The microstructure,mechanical properties,three?dimensional deformation measurement,fracture scanning and XRD were studied.The results showed that the tensile strength was increased by 8.48%and the fracture strain was raised by 9.25%owing to the addition of high frequency ultrasonic vibration to the friction stir welding technology.At the same time,it also effectively improved the upper and lower inhomogeneity of the microstructure of the welded joint,and increased the size of weld bottom cross sections.Particularly,the formation of the defects was inhibited at the bottom of the weld,which can improve the overall strength of the weld.Through the XRD test,it was confirmed that with the decrease of welding temperature,the degree of dissolution of the main strengthening phaseθ″andθ′was reduced,and the coarseθphase particles’s aggregation extent reduced after the addition of ultrasound to the friction stir welding,which improved the mechanical properties greatly.

关 键 词：搅拌摩擦焊 超声振动 三维应变 XRD试验 

分 类 号：TG453.9[金属学及工艺—焊接]