中厚铝合金DP-VPTIG焊接深熔小孔作用机制研究  

Study on the Keyhole Effects in DP-VPTIG Welding of Medium-thick Aluminum Alloys

作　　者：姜自昊 肖宏 曾才有 张权 杨清福 谢非 马康 王亚森 齐铂金[1] 从保强[1] JIANG Zihao;XIAO Hong;ZENG Caiyou;ZHANG Quan;YANG Qingfu;XIE Fei;MA Kang;WANG Yasen;QI Bojin;CONG Baoqiang(School of Mechanical Engineering and Automation,Beihang University,Beijing 100191;Tianjin Aerospace Long March Rocket Manufacturing Co.,Ltd.,Tianjin 300462;China Nuclear Power Engineering Co.,Ltd.,Beijing 100084)

机构地区：[1]北京航空航天大学机械工程及自动化学院,北京100191 [2]天津航天长征火箭制造有限公司,天津300462 [3]中国核电工程有限公司,北京100084

出　　处：《机械工程学报》2025年第6期133-140,共8页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(52075022)。

摘　　要：双频复合脉冲变极性TIG焊通过激发动态深熔小孔实现中厚铝合金结构不开坡口、单面焊双面成形深熔焊接。深熔小孔的动态行为与形貌特征对焊缝熔深有重要影响,为探究小孔对焊缝熔深作用机制,基于高速图像采集技术采集分析小孔于低频脉冲周期、高频脉冲周期以及变极性周期内的动态演变规律;基于双频复合脉冲变极性TIG焊接特点建立焊接过程瞬态数值模型,分析小孔作用下熔池温度场与流场动态特性以及小孔与熔池的关系。结果表明,双频复合脉冲变极性TIG焊熔池随电流脉冲变化而表现出多种动态行为,低频脉冲峰值阶段熔池形成深熔小孔,使焊接热源下移以及于熔池内激发高速流体传热通道,可提高电弧向熔池底部传热的效率,进而促进熔池深度的增加,且小孔深度与熔池深度之间存在互相促进的耦合关系,进一步提升焊缝熔透程度。Double-pulsed variable polarity TIG welding brings about deep penetration welding of medium-thick aluminum alloy structures by stimulating a keyhole in the weld pool.The dynamic behavior and morphological characteristics of the keyhole have a significant impact on the weld formation.In order to explore the effects of the keyhole on the weld penetration,the dynamic evolution law of the keyhole in various pulse cycles is obtained and analyzed by using high-speed image acquisition technology.A transient numerical model of the welding process is established based on computational fluid dynamics.The dynamic characteristics of the temperature field and flow field of the weld pool and the relationship between keyhole and the weld pool are analyzed by using this model.The research results show that the weld pool exhibits various dynamic behaviors with the pulsating current.The keyhole is formed at the low-frequency pulse peak stage,and causes the welding heat source moving downward and excites a high-speed heat transfer channel in the weld pool,which can improve the heat transfer efficiency of the arc towards weld pool bottom and promote the increase of the weld pool depth.Moreover,there is a mutual promotion relation between the depth of keyhole and weld pool,which further improves the penetration.

关 键 词：中厚铝合金结构 脉冲调制电弧 小孔深熔焊 数值模拟 焊缝成形 

分 类 号：TG456[金属学及工艺—焊接]