2219铝合金锻件焊接接头组织与性能  

Structure and properties of welded joint of forging 2219 aluminum alloy

作　　者：宋建岭 孙志鹏 王惠苗 肖宏 刘含伟 

机构地区：[1]天津航天长征火箭制造有限公司,300462

出　　处：《焊接》2014年第7期51-54,74,共4页Welding & Joining

摘　　要：以2219高强铝合金锻件为研究对象,采用变极性TIG焊方法,通过金相分析、拉伸试验及扫描电镜手段分析了焊接接头不同区域显微组织结构、力学性能及断裂形貌。结果表明:2219铝合金锻件焊接接头熔合区由较宽的等轴晶带和粗大的柱状晶组成,热影响区为粗大的等轴非枝晶,打底焊缝中心组织是粗大的等轴非枝晶和等轴枝晶的混合组织,盖面焊缝中心组织是细小的等轴非枝晶组织形态;焊接接头抗拉强度平均值为285 MPa,达到母材强度约65.5%,断后伸长率平均值约3.7%;试样断裂位置均在熔合线附近,打底层断裂形貌呈现典型的韧性断裂特征,盖面断裂形貌以韧性断裂主,局部区域出现解理断裂及层状撕裂的混合特征。Forging alloy of 2219 high strength aluminum was welded by the variable polarity TIG welding method.The microstructure,mechanical properties and fracture morphology in the different area of the welding joint were investigated through the metallographic analysis,tensile test and the scanning electron microscopy.It indicated that the fusion zone of the welding joint were composed of the wide equiaxed grain belt and bulky columnar crystal.The heat affect zone are thick equiaxed non-dendritic,while the center microstructure on backing weld are mixture structure of bulky equiaxed non-dendritic and equiaxed dendritic.In addition,the center microstructure on cap weld are relatively finer and equiaxed non-dendritic structure.The average tensile strength value of the welding joint is 285 MPa,which is 65.5%of the parent metal.The average value of elongation rate is about 3.7%.The position of sample fracture is near the fusion line,the fracture morphology on the root present a typical ductile fracture characteristics,the fracture morphology on the cap are mainly ductile fracture,the local part region show characteristics of cleavage fracture and lamellar tearing.

关 键 词：2219铝合金 变极性TIG焊 显微组织 力学性能 

分 类 号：TG442[金属学及工艺—焊接]