搅拌摩擦焊修复2A12铝合金蒙皮裂纹的接头显微组织与力学性能研究  

Microstructure and Mechanical Properties of Friction Stir Welded Repair Joints for 2A12 Aluminum Alloy Airframe Skin Cracks

作　　者：吴雪猛 刘浩 温泉 闫华伟 赵静[1] WU Xuemeng;LIU Hao;WEN Quan;YAN Huawei;ZHAO Jing(State-owned Sida Machinery Manufacturing Company,Xianyang 712203,China)

机构地区：[1]国营四达机械制造公司,陕西咸阳712203

出　　处：《电焊机》2024年第5期71-77,123,共8页Electric Welding Machine

摘　　要：针对1.5 mm厚2A12-T4飞机铝合金蒙皮裂纹缺陷,采用搅拌摩擦焊(FSW)工艺进行裂纹修复,对FSW接头的显微组织演变、力学性能特征及材料流动行为进行研究。结果表明:修复后接头表面成形较好,弧纹均匀清晰无明显缺陷产生,轴肩作用区边缘出现轻微飞边;接头宏观组织观察到明显的包铝层被搅拌进入基体的现象;接头横截面形貌呈梯形分布,分为母材区、热影响区、热力影响区及搅拌区;搅拌区晶粒发生动态再结晶,形成平均晶粒尺寸为2.68μm的均匀细小等轴晶,远小于平均尺寸为16.94μm的母材区晶粒;修复后接头抗拉强度为379.88 MPa,达到母材强度的91%;修复接头断裂位置发生在前进侧热力影响区附近,断面宏观较平整,但微观存在明显的撕裂棱及韧窝。The crack defect of 1.5mm thick 2A12-T4 aircraft aluminum alloy skin was repaired by friction stir welding(FSW)process.The microstructure evolution,mechanical properties and material flow behavior of the joint were studied.The results show that:the joint surface was well formed after welding.The arc pattern was uniform and clear without obvi‐ous defects.Slight flash occurred at the edge of the shoulder action area.The macrostructure of the joint was observed that the obvious phenomenon that the aluminum-clad layer was stirred into the matrix.The cross section of the joint was trapezoi‐dal and could be divided into base metal zone,heat-affected zone,heat-affected zone and stir-ring zone.Dynamic recrystalli‐zation occurred in the stirring zone.The grains in the stirring zone form uniform fine equiaxed grains with average grain size of 2.68μm.The grain size in the stirring zone was much smaller than the average size of 16.94μm of base metal zone grain.The obtained joint tensile strength was 379.88MPa,reaching 91%of the base metal tensile strength.The fracture position of the joint occurred near the thermal affected zone.The macro section was relatively flat,but there were obvious tearing edges and dimples in the micro section.

关 键 词：2A12铝合金 搅拌摩擦焊 裂纹修复 显微组织 力学性能 材料流动行为 

分 类 号：TG453.9[金属学及工艺—焊接]