氧化膜对6082铝合金搅拌摩擦焊接头疲劳性能的影响

对6 mm厚的6082-T6铝合金进行两种表面处理然后实施搅拌摩擦焊接，研究了对接面氧化膜对接头组织和疲劳性能的影响。结果表明，进行速度为1000 mm/min的高速焊接时，对接面未打磨和打磨的接头焊接质量都良好，接头强度系数达到81%；两种接头的疲劳性能基本相同，疲劳强度均为100 MPa；少数样品在焊核区外断裂，大部分样品在热影响区断裂。与接头相比，两种接头焊核区的疲劳性能有所提高，均为110 MPa，在疲劳测试中裂纹并未沿“S”线萌生和扩展。

Influence of Oxide Film on Fatigue Property of Friction Stir Welded 6082 Al Alloy

The polished and as received 6082-T6 Al sheets of 6 mm in thickness were subjected to friction stir welding (FSW) aiming to revealthe effect of surface oxide film on the microstructure and fatigue property of the FSW joint. The results show that high quality FSW joints with a high joint strength coefficient of 81% could be produced by a high welding speed of 1000 mm/min, for the unpolished and polished butt surfaces. Similar fatigue properties were obtained for the two type of FSW joints with the above two surface states, and the fatigue strength was 100 MPa. Most weld joints failed at the heat affected zones, and only a few weld joints failed at the nugget zone (NZ) during fatigue tests. The fatigue strength increased to 110 MPa for the NZ for plates with the above two surface states, and it is revealed during fatigue test that the fatigue cracks did not initiate on and propagate along the so called“S-line”.