薄壁铝合金搅拌摩擦焊焊接应力变形与控制  

Control of residual stress and distortion in friction stir welded Al sheets

作　　者：李光[1] 李从卿[1] 栾国红[1] 董春林[1] 

机构地区：[1]北京航空制造工程研究所中国搅拌摩擦焊中心,100024

出　　处：《焊接》2009年第1期29-32,共4页Welding & Joining

基　　金：国家科技"十一五"支撑计划重点项目(2006BAF04B09)

摘　　要：搅拌摩擦焊(FSW)焊接残余应力变形表现出与传统熔焊不同的规律,文中研究了薄壁铝合金搅拌摩擦焊残余应力分布规律和焊接变形控制方法,结果表明,纵向残余应力峰值并非出现于焊缝中心,热影响区和热机影响区是残余应力相对较大的区域。基于动态低应力无变形焊接方法,设计开发了一套热沉系统,进行了动态低应力无变形FSW试验。研究表明,动态低应力无变形焊接技术可以有效减小搅拌摩擦焊接头残余应力和变形,接头残余应力分布规律与常规搅拌摩擦焊接头残余应力分布类似,但应力峰值降低50%以上。The distribution of residual stress in thin Al alloy sheets welded by friction stir welding(FSW) shows obvious feature compared with conventional fusion welding.This paper presents the distribution of residual stress and control of welding distortion for friction stir welded Al sheets.It was shown that the peak value of longitudinal stress appears in the edge of FSW tool shoulder instead of the middle of FSW seam. The residual stresses in heat affected zone and thermo-mechanical affected zone is correspondingly higher than that in the other regions.Based on the dynamical control-low stress no distortion(DC-LSND) welding technology,a sink method was used to decrease the residual stress and distortion of FSW joints.The distribution of residual stress of DC-LSND FSW joints is similar with conventional FSW joints.The peak value of residual stress for DC-LSND FSW joint is a half of the ordinary FSW joints approximately.

关 键 词：搅拌摩擦焊 残余应力 动态控制低应力无变形焊接 

分 类 号：TG453[金属学及工艺—焊接]