铝合金T型接头双侧激光同步焊接组织的特征及力学性能  

Microstructure Characteristics and Mechanical Properties of Double-Sided Laser Beam Welded Aluminum Alloy T-Joints

作　　者：陈彦宾[1] 杨志斌[1] 陶汪[1,2] 陈洁 李俐群[1] 刘申[1] 陈磊 

机构地区：[1]哈尔滨工业大学先进焊接与连接国家重点实验室,黑龙江哈尔滨150001 [2]哈尔滨工业大学金属精密热加工国防科技重点实验室,黑龙江哈尔滨150001 [3]国家商用飞机制造工程技术研究中心,上海200436

出　　处：《中国激光》2013年第5期106-112,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(51175115);国家商用飞机制造工程技术研究中心创新基金(SAMC12-JS-15-009)资助课题

摘　　要：针对国产大型客机机身壁板双侧激光同步焊接的铝合金T型接头,系统研究了接头组织特征及力学性能。试验结果表明:从焊缝中心到母材依次存在等轴晶区、柱状晶区、部分熔化区、过热区和母材区5个特征区域,蒙皮侧热影响区是接头最薄弱环节;接头拉伸强度取决于焊缝熔深,平均横向与轴向拉伸强度分别为母材的87.8%和53.1%,试件均起裂于蒙皮焊趾处,断口分别表现为韧性断裂和脆性断裂;平均纵向拉伸强度为母材的90.8%,平均延伸率约为8.4%,断口韧窝小而浅,呈现出韧性与脆性混合断裂特征,熔合线附近焊缝存在撕裂痕迹;疲劳失效首先发生于蒙皮焊趾处并最终断裂于蒙皮,条件疲劳强度约为80.7MPa;焊趾处断口表现出韧性和脆性混合断裂特征,蒙皮位置呈现脆性断裂特征。The microstructure characteristics and mechanical properties of double-sided laser beam welded aluminum alloy T-joints for aircraft fuselage panels are systematically analyed. The experimental results show that five distinct zones are identified between the fusion zone center and the base material which consists cellular dendrite zone, parallel dendrite zone, partially melted zone, over-aged zone, and base material. The heat affected zone of the skin side is the weakest area. The tensile strength depends on the weld penetration, and the failure originates at the weld toe on the skin side. The average transverse and axial tensile strengths reach 87. 8% and 53. 1% of the base materials and the fracture mechanisms of the transverse and axial tensile tests are found to be ductile and brittle fracture, respectively. The average longitudinal tensile strength reaches 90. 8% of the base materials, and the average elongation is 8.4% of the original test specimens. The dimples are small and shallow, the fracture is a mixture of ductile and brittle fracture, and a tearing trace near the fusion line appears. Fatigue failure is found to originate at the weld toe on the skin side and finally crack on the skin, and the conditioned fatigue strength is 80.7 MPa. The fracture at the weld toe is a mixture of ductile and brittle fracture, and the skin panel fracture appears brittle fracture feature.

关 键 词：激光技术 T型接头 双侧激光同步焊接 微观组织特征 力学性能 铝合金 

分 类 号：TG456.7[金属学及工艺—焊接]