焊丝成分对7075Al合金电弧焊熔滴过渡及焊缝成形影响研究

doi:10.3901/JME.2025.20.123

摘要/Abstract

摘要： 7075Al合金由于其优异的机械性能和耐蚀性能而成为一种重要的工业材料，但7075Al合金因其较高的合金元素含量导致焊接性较差，制约了其在复杂连接场合的广泛应用。因此，实现7075Al合金的有效焊接对其进一步推广应用具有重要意义。由此利用ER7075和ER5356焊丝进行7075Al合金的交流冷金属过渡(Advanced cold metal transfer, AC-CMT)电弧焊，通过焊接过程电参数与图像同步采集系统对两种焊丝的熔滴过渡进行了比较研究。在焊丝接阴极(Electrode negative, EN)半波，两种焊丝端部的熔滴均呈规则的椭球状，过渡过程均很稳定，没有明显飞溅。焊丝接阳极(Electrode positive，EP)半波的过渡稳定性明显低于EN半波，ER5356焊丝端部的熔滴呈鸭梨状，有少量飞溅；而ER7075焊丝端部的熔滴呈不规则的长条状，飞溅明显增大；长条状熔滴上下振动，易接触到同样上下振动的熔池，导致异常短路。阳极斑点自动寻找金属蒸发点的特性使得熔滴上的锌(Zn)蒸发激烈而不均匀，这是EP半波飞溅大的主要原因。ER7075焊丝中锌的强烈蒸发使电弧发生明显收缩，降低了焊缝熔宽，增大了熔深能力。尽管ER7075焊丝焊接的焊缝表面氧化较严重，附近也有更多的细小飞溅颗粒，但焊缝成形仍较美观，有细密的鱼鳞纹。在T6热处理状态下，ER7075焊丝焊接的接头抗拉强度比ER5356焊丝高117.8%。

关键词: 冷金属过渡电弧焊, EP半波, EN半波, 飞溅

Abstract: 7075Al alloy is an important industrial material due to its excellent mechanical properties and corrosion resistance. But its high alloy element content results in poor weldability, which limits its wide application in complex connection scenarios. Therefore, the effective welding of 7075Al alloy is of great significance for its further application. The metal transfer behaviors and weld formations in AC-CMT arc welding of 7075 Al alloy with ER7075 and ER5356 wire were comparatively investigated using a synchronized acquisition system for process parameter and image. In the EN (electrode negative) half cycle, the droplets at the ends of both types of welding wires are in a regular elliptical shape, and the transfer processes are both stable without obvious spatter. In EP (electrode positive) half cycle, the molten droplet at the end of ER5356 welding wire takes a pear shape, and is transferred into the weld pool with slight spatter. The droplet at the end of ER7075 welding wire is irregular and elongated, and transferred into the weld pool with increased spatter. The elongated droplet vibrates up and down, which is prone to cause premature contact with the vibrating molten pool surface, resulting in abnormal short circuit. The intense and ununiform Zn evaporation on the droplet enhanced by the anode spots inherently occurring on the metal evaporation sites is the main reason for the increased spatter in EP half cycle. On the other hand, the Zn evaporation causes noticeable arc contraction, reducing the weld fusion width and increasing the penetration capacity. The weld made with ER7075 wire is quite good-looking with fine fish scale patterns, although it is covered a dark oxide film and with much more tiny spatter particles scattered nearby. The tensile strength of the T6 heat-treated joint welded with ER7075 wire is 117.8% higher than that welded with ER5356 wire.

Key words: CMT arc welding, EP half cycle, EN half cycle, spatter

中图分类号:

TG442

王克宽, 牛虎理, 刘剑, 崔琬婷, 李亮玉, 岳建锋. 焊丝成分对7075Al合金电弧焊熔滴过渡及焊缝成形影响研究[J]. 机械工程学报, 2025, 61(20): 123-133.

WANG Kekuan, NIU Huli, LIU Jian, CUI Wanting, LI Liangyu, YUE Jianfeng. Wire Composition Effect on Metal Transfer Behavior and Weld Formation in AC-CMT Arc Welding of 7075Al Alloy[J]. Journal of Mechanical Engineering, 2025, 61(20): 123-133.

参考文献

[1] KANG M，KIM C. A review of joining processes for high strength 7xxx series aluminum alloys[J]. Journal of Welding & Joining，2017，35(6)：79-88.
[2] YENI C，SAYER S，PAKDIL M. Comparison of mechanical and microstructural behaviour of TIG，MIG and friction stir welded 7075 aluminium alloy[J]. Kovove Materialy-metallic Materials，2009，47(5)：341-347.
[3] CEVIK B. Gas tungsten arc welding of 7075 aluminum alloy：microstructure properties，impact strength，and weld defects[J]. Materials. Research Express，2018，5(6)：1-7.
[4] 刘政军，何偲倬，苏允海，等. 焊接材料7075铝合金焊接性及焊缝组织的影响[J]. 沈阳工业大学学报，2018，40(2)：139-144. LIU Zhenjun，HE Sizhuo，SU Yunhai，et al. Influence of different welding materials on weldability and weld bead microstructure of 7075 aluminum alloy[J]. Journal of Shenyang University of Technology，2018，40(2)：139-144.
[5] 闫杨予，胡锦龙，韩启飞，等. 热丝辅助电弧增材Al-Cu-Mg-Ag耐热铝合金组织与性能研究[J]. 机械工程学报，2023，59(11)：242-252. YAN Yangyu，HU Jinlong，HAN Qifei，et al. Microstructure and mechanical properties of Al-Cu-Mg-Ag alloy fabricated by hot-wire arc additive manufacturing[J]. Journal of Mechanical Engineering，2023，59(11)：242-252.
[6] 李国伟，陈芙蓉，韩永全，等. 焊后热处理对7075铝合金PVPPA焊接接头组织与性能的影响[J]. 焊接学报，2018，39(2)：57-60. LI Guowei，CHEN Furong，HAN Yongquan，et al. Influence of post-weld heat treatment on microstructure and mechanical properties of 7075 aluminum alloy P-VPPA welded joint[J]. Transactions of the China Welding Institution，2018，39(2)：57-60.
[7] 高转妮，王磊磊，李响，等. 7075铝合金激光熔丝增材制造热循环和温度梯度对熔池凝固组织的影响研究[J].机械工程学报，2024，60(1)：96-118. GAO Zhuanni，WANG Leilei，LI Xiang，et al. Effect of thermal cycle and temperature gradient on solidification microstructure of deposition layer during 7075 aluminum aalloy laser wire additive manufacturing[J]. Journal of Mechanical Engineering，2024，60(1)：96-118.
[8] 徐腾，张春芝，鲁宽亮，等. 7075铝合金MIG焊接头金相组织、力学性能和耐蚀性的应力敏感性[J]. 焊接学报，2021，42(7)：51-59. XU Teng，ZHANG Chunzhi，LU Kuanliang，et al. Microstructure，mechanical properties and stress dependence of corrosion resistance for MIG welded 7075 aluminum joint[J]. Transactions of the China Welding Institution，2021，42(7)：51-59.
[9] 刘长军，刘政军，阮祥钢，等. 焊后热处理对AA7075铝合金DP-MIG焊接接头组织及力学性能的影响[J]. 焊接学报，2016，37(10)：81-84，88. LIU Changjun，LIU Zhengjun，RUAN Xianggang，et al. Effect of post-weld heat treatment on microstructure and mechanical properties of welded joint of 7075 aluminum alloy by double-plused metal inert-gas welding process[J]. Transactions of the China Welding Institution，2016，37(10)：81-84，88.
[10] REYNA-MONTOYA J S，GARCIA-RENTERIA M A，CRUZ-HERNANDE V L，et al. Effect of electro-magnetic interaction on microstructure and corrosion resistance of 7075 aluminum alloy during modified indirect electric arc welding process[J]. Transaction of Nonferrous Metal Society of China，2019，29(3)：473-484.
[11] ALATORRE N，AMBRIZ R R，NOUREDDINE B，et al. Tensile properties and fusion zone hardening for GMAW and MIEA welds of a 7075-T651 aluminum alloy[J]. Acta Metallurgica Sinica (English Letters)，2014，27(4)：694-704.
[12] 杨智华，杨尚磊，姜亦帅，等. 7075高强铝合金激光填丝焊接组织与力学性能研究[J]. 材料导报，2017，31(12)：60-63，72. YANG Zhihua，YANG Shanglei，JIANG Yishuai，et al. Microstructure and mechanical properties of laser welding joints of 7075 aluminum alloy with filler wire[J]. Materials Report，2017，31(12)：60-63，72.
[13] SONG Gang，WANG Zejie，LIU Zhenfu，et al. Effect of partial rolling on the microstructure and mechanical properties of laser TIG hybrid welded joints of 7075 T6 aluminum alloy[J]. The International Journal of Advanced Manufacturing Technology，2022，121：589-599.
[14] HU B，RICHARDON I M. Microstructure and mechanical properties of AA7075(T6) hybrid laser/GMA welds[J]．Materials Science and Engineering A，2007，459(1-2)：94-100.
[15] WU S C，HU Y N，SONG X P，et al. On the microstructural and mechanical characterization of hybrid laser-welded Al-Zn-Mg-Cu alloys[J]. Journal of Materials Engineering and Performance，2015，24(4)：1540-1550.
[16] 熊斯，唐鑫，王春霞，等. 焊后热处理对Al-Mg-Zn(-Sc-Zr)合金焊丝焊接7075铝合金焊接接头组织和性能的影响[J]. 材料导报，2019，33(8)：2720-2724. XIONG Si，TANG Xin，WANG Chunxia，et al. Effect of post-weld heat treatment on microstructure and mechanical properties of 7075 alloy welded by Al-Mg-Zn(-Sc-Zr) alloy welding wire[J]. Materials Report，2019，33(8)：2720-2724.
[17] 雷正龙，郭亨通，张登明，等. 5A06铝合金超声辅助激光填丝焊接熔池流动与结晶行为研究[J]. 机械工程学报，2021，57(6)：78-86. LEI Zhenglong，GUO Hengtongm，ZHANG Dengming，et al. Study on melt flow and grain refining ultrasonic-assisted laser filler wire welding process of 5A06 aluminum alloy[J]. Journal of Mechanical Engineering，2021，57(6)：78-86.
[18] 吴圣川，谢成，胡雅楠，等. 中高强度铝合金熔化焊接接头的缺陷容限评价方法[J]. 机械工程学报，2020，56(8)：46-59. WU Shengchuan，XIE Cheng，HU Yanan，et al. Defect tolerance assessment method of fusion welded medium and high strength Al alloy joints[J]. Journal of Mechanical Engineering，2020，56(8)：46-59.
[19] 张琨，刘政军. 固溶处理对7075铝合金同质TIG焊接头显微组织及力学性能的影响研究[J]. 热加工工艺，2019，48(3)：83-88，92. ZHANG Kun，LIU Zhengjun. Effect of solution treatment on microstructure and mechanical properties of homogenous TIG welded joint of 7075 aluminum alloy[J]. Hot Working Technology，2019，48(3)：83-88，92.
[20] ZHANG Liang，LI Xiaoyan，NIE Zuoren，et al. Microstructure and mechanical properties of a new Al-Zn-Mg-Cu alloy joints welded by laser beam[J]. Materials & Design，2015，83：451-458.
[21] LIU Xiao，WANG Chenyang，LI Xiaoping，et al. Investigation of 7075 aluminum alloy TIG welding joint using 7075 aluminum alloy wire before and after heat treatment[J]. Material Research Express，2023，10(4)：65-72.
[22] 严铿，施志强，王锡岭. 热处理对喷射成形7XXXX系铝合金TIG焊接头组织与性能的影响[J]. 焊接学报，2012，33(3)：33-40. YAN Keng，SHI Zhiqing，WANG Xiling. Influence of heat treatment on microstructure and mechanical properties of spray formed 7XXX series aluminum alloy TIG weld[J]. Transactions of the China Welding Institution，2012，33(3)：33-40.
[23] FU Gaofeng，TIAN Fuquan，WANG Hong. Studies on softening of heat-affected zone of pulsed-current GMA welded Al–Zn–Mg alloy[J]. Journal of Materials Processing Technology，2006，180：216-220.
[24] YANG Bangjian，FU Zhenghong，LU Ting，et al. Microstructure and fracture toughness properties of CMT repairing welded 7075-T651[J]. Materials Research Express，2019，6(12)：65-69.
[25] ELREFAEY A. Effectiveness of cold metal transfer process for welding 7075 aluminum alloys[J]. Science and Technology of Welding & Joining，2015，20(4)：280-285.
[26] SELVANMANI S T. Microstructure and stress corrosion behavior of CMT welded AA6061 T-6 aluminum alloy joints[J]. Journal of Material Research and Technology，2021，15：315-326.
[27] LI Zhuoxin，OU Lingshan，WANG Yipeng，et al. Solidification cracking restraining mechanism of Al-Cu-Mg-Zn alloy welds using cold metal transfer technique[J]. Materials，2023，16(2)：721.
[28] ZHANG Zhaodong，LANG Qiang，SONG Gang，et al. Microstructure evolution and deformation behavior of TIG welded 7075-T6 aluminum alloy followed by partial hot rolling[J]. Journal of Manufacturing Processes，2023，94：524-538.
[29] HERMANS M J，OUDEN G D. Process behavior and stability in short circuit gas metal arc welding[J]. Welding Journal，1999，78：137S-141S.
[30] CHEN Maoai，ZHANG Dong，WU Chuansong. Current waveform effects on CMT welding of mild steel[J]. Journal of Materials Processing and Technology，2017，243：395-404.
[31] WANG Yuwen，CHEN Maoai，LI Chaofan，et al. Influence of current waveform on C GMAW of 6061 aluminum alloy with addition of ER4043 wire[J]. Welding in the World，2022，66：1093-1109.