2A14-T6铝合金厚板电子束焊接头的显微组织及力学性能  

Microstructure and Mechanical Properties of Electron Beam Welded Joint of 2A14-T6 Aluminum Alloy Thick Plate

作　　者：杨嘉佳 卢明 刘伟 曹慧 倪增磊 YANG Jiajia;LU Ming;LIU Wei;CAO Hui;NI Zenglei(School of Materials Science and Engineering,North China University of Water Resources and Electric Power,Zhengzhou 450045,China;Academy of China Changfeng Electro-Mechanical Technology,Bejing 100854,China;Beijing Aerospace Xinli Technology Co.,Ltd.,Bejing 100039,China)

机构地区：[1]华北水利水电大学材料学院,河南郑州450045 [2]中国长峰机电技术研究设计院,北京100854 [3]北京航天新立科技有限公司,北京100039

出　　处：《热加工工艺》2024年第6期93-96,101,共5页Hot Working Technology

基　　金：华北水利水电大学高层次人才科研资助启动项目(4001/40678)。

摘　　要：对24 mm厚2A14-T6铝合金板开展了电子束焊接试验,获得了最佳的焊接工艺参数。结果表明:接头变形小、深宽比大,探伤结果为I级。接头各微区组织具有差异性,焊缝中心组织为树枝晶,近熔合线处的焊缝组织为柱状晶,热影响区组织为粗化的扁长纤维状组织,沉淀强化相颗粒增多,过时效区组织与母材相近,均为扁长纤维状组织。焊缝区晶粒内有少量沉淀强化相,晶界上存在由铜、硅等元素与基体相形成的共晶相,呈网络状分布;母材区有细小的Al_(2)Cu沉淀强化相及呈条状分布的大块共晶相。焊缝区显微硬度最低,热影响区硬度随距焊缝中心距离增大先上升后下降,母材区的最高。接头的平均抗拉强度和断后伸长率分别为387.7 MPa和3.4%,微观断口有撕裂棱和少量大而浅的韧窝,为脆性为主的韧脆混合型断裂。The electron beam welding tests of 24 mm thick 2A14-T6 aluminum alloy plate were carried out,and the best welding process parameters were obtained.The results show that the joint deformation is small,the depth-width ratio is large,and the flaw detection result is Grade I.The microstructure of each micro-area of the joint is different.The center of the weld is dendrite,the microstructure of the weld near the fusion line is columnar grains,the heat-affected zone is coarsened oblate fibrous structure,the precipitation strengthening phase particles increase,and the microstructure of the over-aging zone is similar to that of the base metal,which is oblate fibrous structure.There is a small amount of precipitation strengthening phases in the grain of the weld zone,and there are eutectic phases formed by copper,silicon and other elements and the matrix phase at the grain boundary,which are distributed in network shape.There are fine Al_(2)Cu precipitation strengthening phase and massive eutectic phase distributed in strip shape in the base metal zone.The microhardness of the weld zone is the lowest,that of the heat-affected zone rises first and then decreases with the increase of the distance form the weld center,and that of the base metal zone is the highest.The average tensile strength and elongation after fracture of the joint are 387.7 MPa and 3.4%respectively.There are tearing edges and a small number of large and shallow dimples on the micro-fracture,which is a brittle-ductile mixed fracture mainly characterized by brittleness.

关 键 词：电子束焊 2A14-T6铝合金 显微组织 力学性能 

分 类 号：TG457.14[金属学及工艺—焊接]