7003-T7铝合金的搅拌摩擦焊接头组织与性能

Microstructure and properties of friction stir welding joint of 7003-T7 aluminum alloy

采用金相显微镜、布氏硬度计和万能试验机等手段,实验研究7003-T7铝合金的搅拌摩擦焊焊接接头的组织与性能。实验结果表明:搅拌摩擦焊焊接接头组织焊核区和热机影响区前进侧分界明显,后退侧相对模糊。由于焊接搅拌针机械搅拌的作用,使焊核区表现为细小的等轴晶组织,其晶粒尺寸小于8μm。焊接接头组织中,母材的硬度值为HB97 ,焊核区的硬度值为HB110,热影响区最低处的硬度值为HB84,焊接接头性能系数为86%。

Microstructure and properties of friction stir welding joint of 7003-T7 aluminum alloy were studied by means of metallographic microscope,Brinell hardness tester and universal testing machine. The results show that there is a clear boundary between advancing sides of the nucleus zone and the thermo-mechanically affected zone( TMAZ),and that of retreating sides is relatively fuzzy. As a result of the mechanical stirring of the welding stirring needle,the microstructure of the weld core was fine equiaxial crystal with grain size less than8 μm. Hardness of the base metal,hardness of the welded nugget,hardness of the lowest heat affected zone and property coefficient of welded joint are HB97,HB110,HB84 and 86%,respectively.