焊接速度对7050-T7451铝合金搅拌摩擦焊接头疲劳性能的影响  

Effect of Welding Speed on Microstructure and Fatigue Property of 7050-T7451 Aluminum Alloy by Friction Stir Welding

作　　者：王希靖[1] 张杰[1] 牛勇[1] 李树伟[1] 徐成[1] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料国家重点实验室,兰州730050

出　　处：《宇航材料工艺》2008年第4期66-69,共4页Aerospace Materials & Technology

基　　金：国家自然科学基金资助项目(10577010)

摘　　要：针对5mm厚航空用铝合金7050-T7451进行了不同焊速时搅拌摩擦焊接头的微观结构和低周疲劳性能的研究。结果表明:接头焊核区面积与焊核区晶粒度都随着焊接速度的增加而减小;转速为400r/min、焊速为40mm/min时,接头具有最好的疲劳性能;搅拌摩擦焊接头的低周疲劳裂纹均在接头底部启裂,沿前进侧热机械影响区与焊核区的过渡区域扩展至断裂。In this paper,the microstructure and low cycle fatigue properties of friction stir welded 5mm-thick aero aluminum alloy 7050-T7451 were investigated under different welding speed.The results show that as welding speed increasing,there is a considerable decrease for weld nugget aera and grain size.The best low cycle fatigue life is obtained with the rotating speed of stirring joint at 400 r/min and welding speed at 40 mm/min.The fatigue cracks initiate from the root of the welds,and then propagate to fractur...

关 键 词：搅拌摩擦焊 7050-T7451铝合金 微观结构 低周疲劳 焊接速度 

分 类 号：TG407[金属学及工艺—焊接]