新型铝合金板材双面焊接头性能研究  

Performance of a New Aluminum Alloy Joint with Butt-Weld

作　　者：孙建通[1] 李晓延[1] 张亮[1] 兖文涛 杨秦政 Sun Jiantong Li Xiaoyan Zhang Liang Yan Wentao Yang Qinzheng(Beijing University of Technology, Beijing 100124, China)

机构地区：[1]北京工业大学,北京100124

出　　处：《稀有金属材料与工程》2017年第9期2607-2612,共6页Rare Metal Materials and Engineering

基　　金：国家"973"项目资助(2012CB619503)

摘　　要：针对一种新型Al-Zn-Mg-Cu合金进行双面MIG焊接,观察接头部位组织形貌,并进行显微硬度测试,然后基于visual-weld进行温度场的仿真计算,建立接头部位温度场与组织形貌和硬度的关系。然后采用X射线法对焊件进行残余应力测试。结果表明,焊缝中心为粗大等轴树枝状晶,靠近熔合线存在一个细晶层,在细晶层内侧为典型的联生结晶形貌,熔合线外侧出现部分晶界重熔;焊接件残余应力较小,两端应力分布趋势相反,其它部位分布基本相同。由于温度循环和η相的影响,在接头热影响区位置,硬度值明显高于母材和焊缝。A new type Al-Zn-Mg-Cu alloy was welded using Tungsten Inert Gas welding method. Microstructures and microhardness of the joint were analyzed. The relationship of the temperature with microstructure and microhardness was established based on the simulation result of the temperature field through the Visual-weld. At last,the residual stress was tested by the X-ray diffraction method. The results show that microstructure in the weld seam is a coarse equiaxed grain zone（EQZ）. That zone close to the fusion line is an equiaxed grain zone with small size,which is as called Fine-Grain Layer. For the Fine-Grain layer,microstructure exhibits epitaxial solidification morphology. However,partial grain boundary re-melt appears outside of fusion line. Residual stress in the weldment is small and has almost the same distribution in the stable forming segment of weld seam. However,it has an inverse distribution in the front end of weld seam. With the influence of temperature curve of welding and η phase,microhardness in the hot affected zone is bigger than that in other zones in the weldment.

关 键 词：双面MIG焊接 AL-ZN-MG-CU合金 残余应力 微观形貌 显微硬度 

分 类 号：TG407[金属学及工艺—焊接]