对6mm厚的航空用AA7050-T7451、AA2024-T4铝合金进行了同种和异种材料的搅拌摩擦焊接, 并对3种接头的拉伸特性和断口进行了分析。试验结果表明, 同种材料接头的强度极限达到母材的90%以上, 屈服极限达到母材的75%以上, AA7050/AA2024 FSW接头强度分别达到AA7050母材和AA2024母材的60.5%和70.8%, 屈服极限分别达到AA7050母材和AA2024母材的46.2%和75.5%;焊缝焊核区由细小均匀的等轴晶粒组成, 热机影响区颗粒粗化并发生扭曲变形, 热影响区晶粒受循环热影响变得粗大;拉伸试验断裂发生在前进侧热机影响区/热影响区的过渡段, 断口存在明显的韧窝, 整体属于韧性断裂。
This paper deals with the tensilel properties through jointing AA7050-T7451 and AA2024-T4 aluminum alloys in aviation by friction stir weld and analyzing fracture surfaces.The results show that the ultimate strength can reach 90%, the yield limit can reach 75%, the ultimate strength of AA7050/AA2024 FSW joint can reach 60.5% of AA7050 and 70.8% of AA2024.The yield limit can reach 46.2 % of AA7050 and 75.5% of AA2024.The equi-axial fine grains are found in the weld nugget, the coarse and distorted grains in the thermo-mechanically affected zone, and coarse grains in the heat affected zone.The fractures occur at the advancing side between thermo-mechanically affected zone and heat affected zone.Dimples appear on the fracture surfaces, which means that the fractures are ductile fracture.
[1]严铿, 蒋成禹, 李敬勇, 等.先进的搅拌摩擦焊[J]. 轻合金加工技术, 2003(11):37-40.
[2]栾国红, 郭德伦, 关桥, 等.飞机制造工业中的搅拌摩擦焊研究[J].航空制造技术, 2002(10):43-46.
[3]Kar-Erik Knipstim, Pekari Bertil.Frication stir welding process goes commercial[J].Welding Journal, 1997, 76(9):55-56.
[4]徐春容, 王世忠, 徐蒋明.搅拌摩擦焊技术在核工业中的应用[J].金属铸锻焊技术, 2008(7):122-124.
[5]A.GERLICH, P.SU, T.H.NORTH.Tool penetration during friction stir spot welding of Al and Mg alloys[J].Journal of Materials Science, 2005(40):6473-6481.
[6]Minak G, Ceschini L, Boromei I, et al.Fatigue properties of friction stir welded particulate reinforced aluminium matrix composites[J].International Journal of Fatigue, 2010(32):218-226.
[7]Cavaliere P, Rossi G L, Di Sante R, et al.Thermoelasticity for the evaluation of fatigue behavior of 7005/ Al2O3/10p metal matrix composite sheets joined by FSW[J].International Journal of Fatigue, 2008(30):198-206.
[8]Rodrigues D M, Loureiro A, Leitao C, et al.Influence of friction stir welding parameters on the microstructural and mechanical properties of AA 6016-T4 thin welds[J].Materials and Design, 2009(30):1913-1921.
[9]张洪武, 张昭, 陈金涛.搅拌摩擦焊接过程的有限元模拟[J].焊接学报, 2005, 26(9):22-27, 4.
[10]崔约贤, 王长利.金属断口分析[M].哈尔滨:哈尔滨工业大学出版社, 1998.
