CORROSION BEHAVIOR OF FRICTION STIR WELDED JOINT OF 7075 ALUMINUM ALLOY BY ACID SALT SPRAY
酸性盐雾中7075铝合金搅拌摩擦焊接头的腐蚀行为

The microstructure of friction stir welded(FSW)joint of 7075 aluminum alloy was examined by means of optical microscope and transmission electron microscope.The corrosion behavior of the joint was investigated by acidic salt spray and then the macroscopical and microscopical appearances of the corroded surface were observed by using of scanning electron microscope. The results show that the size of the grain and the second phase particles in the weld zone surface are obviously refined.The resistance to corrosion of FSW seam is lower than that of the pure aluminum clad alloy.The corrosion of the FSW joint is rather un-uniform.The initial corrosion occurred as pitting corrosion and finally developed to be exfoliation.