摘要
采用不同焊接速度对6005A-T5铝合金进行搅拌摩擦焊,对其焊接接头的组织和力学性能进行研究。建立了不同焊接接头区域析出相的演变和力学性能之间的关系。在焊接的过程中,焊核区由于受到了足够的热输入,β″相完全回溶到铝基体。在后续的自然时效过程中逐渐形成GP区,这也是焊核区硬度上升的主要原因。热影响区发生不完全再结晶,晶粒呈现拉长状,同时有大量的位错形成。热影响区主要包含Q’相和β″相。当焊接速度下降时,焊接接头的强度随着β″相的回溶和Q’相的形成逐渐降低。焊接接头纵向残余应力的平均值要大于横向残余应力。当焊接速度增加,纵向残余应力的峰值随之增加,但对横向残余应力的影响可以忽略。
The 6005 A-T5 aluminum alloy welded joints were prepared by friction stir welding(FSW) at different welding speeds. The microstructure and mechanical properties of these joints were investigated. The relationship between evolution of precipitates in different regions and mechanical properties of welded joints was established. The results show that β″ phases completely dissolve back into the aluminum matrix due to sufficient welding heat input in nugget zone(NZ) during the welding processing. GP zones form during the subsequent natural aging, which results in the hardness recovery of NZ. Incomplete recrystallization occurs in the thermo-mechanically affected zone(TMAZ), and the grains are elongated with high dislocation density. The heat affected zone(HAZ) contains Q’ and β″ phases. With the decrease of welding speed, β″ phase gradually disappears and Q’ phase forms, which leads to a decrease in the strength of welded joints. The average value of longitudinal residual stress is higher than that of transverse residual stress. With the increase of welding speed, the peak longitudinal residual tensile stress increases, but the effect on the transverse residual tensile stress is negligible.
作者
刘敬萱
沈健
李锡武
闫丽珍
闫宏伟
刘红伟
温凯
李志辉
张永安
熊柏青
Liu Jingxuan;Shen Jian;Li Xiwu;Yan Lizhen;Yan Hongwei;Liu Hongwei;Wen Kai;Li Zhihui;Zhang Yong’an;Xiong Baiqing(State Key Laboratory of Nonferrous Metals and Processes,GRIMAT Engineering Institute Co.,Ltd,Beijing 101407,China;GRINM Group Co.,Ltd,Beijing 100088,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2019年第12期3797-3805,共9页
Rare Metal Materials and Engineering
基金
National Key R&D Program of China（2016YFB0300905,2016YFB0300902）
关键词
铝合金
搅拌摩擦焊
组织
力学性能
残余应力
aluminum alloy
friction stir welding
microstructure
mechanical properties
residual stress
