2219铝合金双脉冲VP-GTAW接头组织与性能  

Microstructure and Properties of 2219 Aluminum Alloy Welded Joint Produced by Double-Pulsed VP-GTAW Process

作　　者：从保强[1,2] 樊弢 齐铂金 王义朋[1,2] 祁泽武 CONG Baoqiang;FAN Tao;QI Bojin;WANG Yipeng;QI Zewu(School of Mechanical Engineering and Automation,Beihang University,Beijing 100191,China;MIIT Key Laboratory of Aeronautics Intelligent Manufacturing,Beijing 100191,China)

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]航空高端装备智能制造工信部重点实验室,北京100191

出　　处：《航空制造技术》2018年第20期16-21,共6页Aeronautical Manufacturing Technology

基　　金：北京市自然科学基金项目(3182020)

摘　　要：以4mm 2219-T87高强铝合金平板为对象,分别使用ER2319 Al-Cu焊丝和ER5087 Al-Mg焊丝作为填充材料,研究双脉冲变极性钨极氩弧焊(VP-GTAW)对接接头的显微组织和力学性能。结果表明,与常规VP-GTAW工艺相比,对焊接电流进行低频脉冲调制的双脉冲VP-GTAW工艺可细化晶粒,改善焊缝显微组织;提高对接接头力学性能,且抗拉强度和断后伸长率均在低频脉冲频率为2Hz时达到最大值。与Al-Cu焊丝接头相比,Al-Mg焊丝接头可以在保持对接接头塑性的同时,提高抗拉强度和显微硬度,抗拉强度最大为328MPa,达到母材的72%;焊缝区显微硬度达到100HV以上。Al-Cu焊丝接头和Al-Mg焊丝接头均为脆性-韧性混合断裂。The butt welding experiments were carried out using double-pulsed variable polarity gas tungsten arc welding （VP-GTAW） process with 4mm 2219-T87 high strength aluminum alloy as base metal, and ER2319 Al-Cu wire and ER5087 Al-Mg wire as filler wire, respectively. The microstructure and mechanical properties of welded joints were investigated. The results show that double-pulsed VP-GTAW process has benefits on refining grain size and improving mechanical properties. The maximum tensile strength and elongation can be achieved when the frequency of low-frequency pulse frequency is 2Hz. The tensile strength and microhardness of the 2219 aluminum alloy welded joints using Al-Mg wire are superior to that using Al-Cu wire with similar plastic property. The maximum tensile strength is 328MPa, which is 72% of base metal. The microhardness of weld zone is above 100HV. Fracture pattern of all welded joints is mixed fracture of brittle and ductile.

关 键 词：2219铝合金 双脉冲VP-GTAW 显微组织 力学性能 脉冲调制 

分 类 号：TG407[金属学及工艺—焊接]