宇航材料工艺http：//www.yhclgy.com2023年第1期2219铝合金厚板TIG焊接头组织与力学性能研究陈志元张晓鸿林鹏范翼飞黄色贤（四川航天长征装备制造有限公司，成都610100）文摘采用氦弧打底+氩弧填充、盖面的焊接工艺对2219-T87铝合金15mm厚板进行TIG焊接试验，研究其焊缝成形和组织力学性能。结果表明，此工艺焊缝成形美观，无可见焊接缺陷，气孔抑制效果好，接头平均抗拉强度为278.22MPa，平均断后延伸率为3.89%，接头平均强度系数达到58.94%。接头硬度整体表现为焊缝中心最低，从焊缝中心到母材呈现先增大后局部降低再增大的趋势；且焊缝中心填充层硬度高于打底层和盖面层。熔合区的微观组织为柱状树枝晶和胞状树枝晶，且垂直于熔合线生长，在靠近熔合区两侧出现了等轴细晶带。焊接接头断面有较多撕裂棱和韧窝，局部发现第二相粒子和微孔，其断裂机制为典型的韧性断裂。关键词2219铝合金，厚板TIG焊，微观组织，力学性能中图分类号：TG444.2DOI：10.12044/j.issn.1007-2330.2023.01.009ResearchonJointMicrostructureandMechanicalPropertiesofTIGWeldingof2219AluminumAlloyThickPlateCHENZhiyuanZHANGXiaohongLINPengFANYifeiHUANGSexian（SichuanAerospaceChangzhengEquipmentManufacturingCo.，Ltd.，Chengdu610100）AbstractInthispaper，theweldingprocessofheliumarcbottoming+argonarcfillingandcoveringwasusedtoconductTIGweldingexperimenton15mmthickplateof2219-T87aluminumalloytostudyitsweldformation，microstructureandmechanicalproperties.Theresultsshowthatthisprocesshasgoodweldappearance，novisibleweldingdefects，andgoodporosityinhibitioneffect.Theaveragetensilestrengthofthejointis278.22MPa，theaverageelongationafterfractureis3.89%，andtheaveragestrengthcoefficientofthejointreaches58.94%.Theoverallperformanceofthejointhardnessisthelowestinthecenteroftheweld.Fromthecenteroftheweldtothebasematerial，thehardnessfirstincreases，thendecreaseslocally，andthenincreases；andthehardnessofthefillerlayerinthecenteroftheweldishigherthanthatofthebottomlayerandthecoverlayer.Themicrostructureofthefusionzoneiscolumnardendriteandcellulardendrite，andgrowsperpendiculartothefusionline.Equiaxedfinegrainbandsappearonbothsidesofthefusionzone.Therearemanytearingedgesanddimpleso...
