2系铝合金的搅拌摩擦焊接接头微观组织与力学性能研究  

Microstructure and Mechanical Properties of Friction Stir Welded Joints of 2××× Aluminum Alloy

作　　者：陈平[1] CHEN Ping(College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

机构地区：[1]南京航空航天大学航空学院,南京210016

出　　处：《北京印刷学院学报》2024年第3期32-37,共6页Journal of Beijing Institute of Graphic Communication

摘　　要：采用搅拌摩擦焊对铝板进行对接焊试验,具体形式为单面焊双面成型,采用拉伸机和显微维氏硬度仪对试样进行力学性能测试,利用蔡司金相与扫描电子显微镜研究母材和焊接接头的微观组织。结果表明,在微观组织方面,前进速度不变时,随旋转速度的增加,材料焊合区的组织更均匀,晶粒尺寸更为细小均匀致密;热机影响区存在有板条状的粗大组织和细小的等轴晶,且晶粒尺寸在逐渐变小;热影响区平均晶粒尺寸呈现增大的趋势。在硬度方面,焊接接头硬度热影响区最低,搅拌焊合区次之,热机影响区位于二者之间。在拉伸方面,不同焊接工艺下试样的拉伸断裂位置均在铝合金的焊接接头处,焊接接头断口呈现比较明显的韧性断裂特征。1000r·min^(-1)及100mm/min下的焊接接头的断裂伸长率为17.1%、抗拉强度可以达到410MPa,其焊接接头的力学性能最优。由此得出结论,铝合金搅拌摩擦焊可以获得性能比较优良的焊接接头,可为其他铝合金材料的FSW焊接提供技术参考。The work aims to study the structure and mechanical properties of aluminum alloy friction stir welding(FSW).The butt welding experiment of aluminum plate was carried out through FSW in the specific form of single-sided welding double-sided forming.The tensile machine and micro Vickers hardness tester were used to test the mechanical properties of the samples.The micro-structures of base metal and welded joint were studied with Zeiss metallography and scanning electron microscope.The results showed that microstructure of the nugget zone are more uniform and finer with the increase of the rotation speed.In the heat-mechanics affected zone,there are large plate-like structures and a fine equiaxial crystal,the grain size is gradually decreasing.The average grain size of the heat affected zone showed an increasing trend.The hardness of heat affected zone is the lowest,followed by nugget zone.The tensile fracture position of the samples under different welding processes is all at the welded joint of the aluminum alloy,the fracture of the welded joint shows obvious ductile fracture characteristics.The elongation of FSW joints under 1000r·min^(-1) and 100mm/min is 17.1%,the tensile strength is 410MPa,the mechanical properties of the welded joint under 1000r·min^(-1) and 100mm/min are the best.

关 键 词：搅拌摩擦焊 2系铝合金 微观组织 力学性能 

分 类 号：TG453[金属学及工艺—焊接]