时效温度对7075铝合金搅拌摩擦焊构件焊缝组织及性能的影响  

Influences of aging temperature on microscopic organization and mechanical properties of aluminum alloy 7075 for FSW component

作　　者：黎俊初[1] 覃雯[1] 刘大海[1] 谢吉林[1] 

机构地区：[1]南昌航空大学航空制造工程学院,江西南昌330063

出　　处：《锻压技术》2016年第7期91-96,共6页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51375220);江西省优势科技创新团队资助项目(CB201503100)

摘　　要：对7075铝合金搅拌摩擦焊T形构件进行相同时间、不同温度的时效处理,并对处理过程进行了分析。试验依据时效温度分为6组,从140℃以20℃等差递增至240℃,统一选定时效时间为4 h。给出了时效温度对焊缝区域电导率、拉伸强度及伸长率的影响规律,并通过焊缝区金相组织及断口扫描分析解释了力学性能变化的原因。结果表明,室温下随着时效温度的增高,电导率增加;低于160℃时效时工件抗拉强度变化不大,抗拉强度在160℃时达到峰值331.8 MPa,随着时效温度的增加,抗拉强度明显下降;工件伸长率在140℃到180℃时效后出现小幅波动,超过200℃时效后明显增加。The aluminum alloy 7075 FSW T-beam was aged by the same time and different temperatures,and the aging process was analyzed. The experiments were carried out by dividing six groups according to the aging temperature from 140 ℃ to 240 ℃ with interval20 ℃ and the aging time 4 h. The influence regulations of aging temperature on conductivity,tensile strength and elongation were given respectively,and the cause of mechanical properties change was explained by analyzing the metallographic microscopes of the welding line and SEM images of fracture morphology. The results show that conductivity increases with the increase of aging temperature at room temperature,and the tensile strength of workpiece changes little below 160 ℃. Then,the tensile strength decreases significantly with the increase of aging temperature,and reaches the peak of 331. 8 MPa at 160 ℃. However,the elongation slightly fluctuates between aging processes from 140 ℃ to 180 ℃,and significantly increases above 200 ℃.

关 键 词：时效温度 7075铝合金 搅拌摩擦焊 力学性能 电导率 

分 类 号：TG453.9[金属学及工艺—焊接] TG156.92