摘要
分别采用普通搅拌摩擦焊和超声搅拌摩擦焊对7022铝合金进行焊接实验,并对焊接接头的力学特性、微观组织和断口形貌进行比较。结果表明:超声搅拌摩擦焊焊接接头的平均抗拉强度、屈服强度都比普通搅拌摩擦焊焊接接头有所提高;焊缝区的晶粒尺寸比普通搅拌摩擦焊晶粒更细小,其组织更均匀、致密。超声振动能量被成功注入到搅拌摩擦焊的焊缝区,在热效应、体积效应和振动效应综合作用下,焊缝区晶体位错移动加强、热塑化加剧,流动阻力减小,中底部热量增加,促使晶粒细化和组织均匀化,从而提高了综合力学性能。
Common FSW and ultrasonic FSW welding experiments were conducted on 7022 aluminum alloy,and the mechanical properties of welding joint,microstructure and fracture morphology were compared. Test results show that the average tensile strength and yield strength of the ultrasonic FSW welding joint are higher than those of common FSW welding joint. The grain size in weld zone is finer than that of common friction stir welding,the microstructure becomes more even and more compact. This shows that ultrasonic vibration energy is successfully injected to FSW weld zone,crystal dislocation movement of weld zone becomes more strengthened,thermal plasticizing intensifies,flow resistance decreases and the bottom heat increases by heating effect,volume effect and vibration effect. The comprehensive mechanical properties are improved due to grain refinement and microstructure homogenization.
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2013年第6期22-25,共4页
Ordnance Material Science and Engineering
基金
湖南省教育厅自然科学研究项目(项目编号:11C1290)
关键词
搅拌摩擦焊
超声振动
力学特性
金相组织
FSW
ultrasonic Vibration
mechanical property
metallographic microstructure
