摘要
主要研究时效处理温度和时效保温时间对7075铝合金激光焊接头组织和性能的变化规律,使用扫描电镜观察焊接过程中形成的链条状的T相随着保温时间的延长,逐渐熔断进入基体,时效处理温度120℃保温24 h后T相呈均匀分布的球状,减少了其对基体的割裂作用。通过TEM和SAED花样可以看出[011]_(Al)、[112]_(Al)、[001]_(Al)晶带轴均析出纳米级强化相η'相,阻碍位错运动,提高焊缝的力学性能,随着时间的延长η'相尺寸、分布密度发生变化,逐渐变成η相。通过对比显微硬度和抗拉强度,时效处理温度120℃保温24 h时7075铝合金激光焊接头的力学性能最好。
Effect of aging temperature and aging time on the microstructure and performance of 7075 aluminum alloy laser weld were studied.Scanning electron microscopy(SEM)was used to observe the formed chain T phase during welding.With the extension of heat preservation time,the T phase melts into the substrate gradually.After aging treatment at 120℃ for 24 h,the T phase is uniformly distributed in a spherical shape,which reduces its cleavage effect on the matrix.TEM and SAED pattern show that the nanoscaleη'phase is precipitated on the crystal axis of[011]_(Al),[112]_(Al),[001]_(Al),which prevents dislocation movement to improve the mechanical properties of welds.With the extension of time,the size and distribution density ofη'change andη'phase gradually becomeηphase.By comparing the microhardness and tensile strength,7075 aluminum alloy laser welded joint has the best mechanical properties after aging treatment at 120℃ for 24 h.
作者
丁亚茹
陈芙蓉
Ding Yaru;Chen Furong(School of Materials Science and Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;Inner Mongolia Technical College of Electrical and Mechanical,Hohhot 010051,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2021年第11期4051-4058,共8页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51765053)
内蒙古自治区草原英才(DC1800007434)
内蒙古自治区轻金属材料重点实验室(2017MS0502)。
关键词
7075铝合金
激光焊接头
时效处理
纳米级强化相
7075 aluminum alloy
laser welding joint
aging treatment
nanoscale strengthening phase
