冷却条件对5E83铝合金搅拌摩擦焊接头组织与性能的影响

通过光学显微镜、扫描电镜(SEM)、电子背散射衍射(EBSD)、显微硬度试验和拉伸试验,研究了转速为400、800、1200 r/min时,水冷和空冷对5E83铝合金搅拌摩擦焊接头组织与性能的影响。结果表明,与空冷条件相比,水冷条件下搅拌摩擦焊接头产生的飞边减少,洋葱环形成区域缩减、焊核区的硬度明显提高。当转速为800 r/min时,与空冷条件相比,水冷条件下接头的抗拉强度提高,接头效率提高11%,硬度提高11%,同时焊核区的平均晶粒尺寸减小43%,但空冷条件下接头断口的韧窝大而深,塑性较好,水冷条件下的断口韧窝小而浅,塑性下降。

Effect of cooling condition on microstructure and properties of friction stir welded joints of 5E83 aluminum alloy

Effect of water-cooling and air-cooling condition on microstructure and properties of the friction stir welded (FSW) joints of 5E83 aluminum alloy at rotation speed of 400, 800, 1200 r/min was investigated by means of optical microscope, scanning electron microscope (SEM), electron backscattered diffraction (EBSD), microhardness test and tensile test. The results show that compared with air-cooling condition, the flash of friction stir welded joints under water-cooling condition and the onion ring formation area reduce, while the hardness of the weld nugget area is significantly improved. When the rotation speed is 800 r/min compared with air-cooling, the tensile strength of the joint under water-cooling is improved, the joint efficiency is increased by 11%, the hardness is increased by 11%, and the average grain size of the weld nugget area is reduced by 43%. However, the fracture dimples of the joint under the air cooling condition are large and deep, and the plasticity is better, while the fracture dimples under the water-cooling condition are small and shallow, and the plasticity decreases.