Effect of Processing Parameters on Microstructure and Corrosion Behavior of Friction Stir Welded 2024 Aluminum Alloy
焊接参数对2024铝合金FSW接头组织及腐蚀行为的影响

Friction stir welding (FSW) for 2024 aluminum alloy sheets was conducted by different processing parameters. The microstructure of the surface and the corrosion behavior in EXCO solution of joints were investigated. The correlation between the micro-hardness profile and the corrosion sensitive region was discussed. The results show that grains in the shoulder active zone (SAZ) are obviously refined. With increasing the rotation speed, the spans of heat-affected zone (HAZ) widens, furthermore, the hardness of the SAZ increases and the corrosion resistance of this region enhances. When the rotation speed is 1500 r/min and weld speed is 1000 mm/min, the plasticity metal flow is more intensive, and the hardness value of the SAZ comes up almost to that of the base metal, therewith, only pitting corrosion occurred in the joint after being immersed 10 h in EXCO solution. Compared with the base metal, the softened zone coincides with the corrosion sensitive region. However, there is not strict correlation.