摘要
对7003铝合金实施钨极氩弧焊(GTAW),并分别进行焊后AA和T6热处理。利用拉伸机、硬度仪和透射电子显微镜(TEM)研究热处理对焊缝抗拉强度、显微硬度和析出相的影响。结果表明,与AA热处理相比,T6热处理可有效促进焊缝中Zn和Mg元素由高浓度区域向低浓度区域扩散,且扩散较均匀,可起到较好的析出强化作用,从而有效提升母材和焊缝区硬度,减小母材和焊缝区之间的硬度差异,分别使焊缝区和母材硬度提升41%和24%。经T6热处理的焊缝出现30nm宽的无沉淀析出带,且基底分布着细小的η′相析出物,阻碍位错滑移,焊缝抗拉强度较大,达到348 MPa。
Gas tungsten arc welding （GTAW） was conducted on 7003 aluminum alloy and the weld was heat treated under AA andT6 heat treatment eonditions. The effect of heat treatment on the tensile strength, microstructure and precipitated phase of theweld was studied by means of tensile tester, electron microscope and transmission electron microscope （TEM）. The results showthat compared with AA heat treatment, T6 heat treatment can effectively promote the diffusion of Zn and Mg elements in the weldfrom the high concentration region to the low concentration area, which makes the element diffusion more uniform and theprecipitation strengthening effect better. T6 heat treatment can effectively reduce the hardness gap between the weld zone and thebase metal and improve the hardness of the weld zone and the base metal by 41% and 24%, respectively. The precipitation-freezone, 30 nm in width, appears in the weld after T6 heat treatment. The distribution of the fine phase precipitates in thesubstrate of T6 heat treated welds can block dislocation movement. The tensile strength of the weld with T6 heat treatmentreaches 348 MPa, which is higher than that of the weld with AA heat treatment and without any heat treatment.
作者
刘守法
王晋鹏
LIU Shoufa, WANG Jinpeng2(1.School of Mechanical Engineering, Xijing University, Xi＇an 710123, China; 2.School of Mechanical ＆ Electrical Engineering, Northwestern Polytechnical Unive~ity, Xi＇an 710072, Chin)
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2018年第2期22-25,共4页
Ordnance Material Science and Engineering
基金
国家科技重大专项基金(2017ZX04011010)
陕西省教育厅专项科研计划项目(15JK2172)
西京学院科研基金(XJ160120)
关键词
钨极氩弧焊
热处理
抗拉强度
无沉淀析出带
位错滑移
gas tungsten arc welding
heat treatment
tensile strength
precipitation-free zone
dislocation movement
