6061铝合金FSW接头组织与耐蚀性能的研究

Study on Microstructure and Corrosion Resistance of 6061 Aluminium Alloy Friction Stir Welded Joint

对4 mm厚的6061-T6铝合金板进行了搅拌摩擦焊接,通过浸泡腐蚀试验和电化学腐蚀试验研究焊缝腐蚀性能,采用金相显微镜、透射电镜等观察接头的微观组织。结果表明:6061铝合金FSW焊核区晶粒显著细化,晶界第二相较少;焊核区的耐剥落腐蚀和晶间腐蚀性能优于热影响区的;焊核区比热影响区的腐蚀电位较高,腐蚀电流密度较小,焊核区表现出更好的耐腐蚀性能。

The friction stir welding of 4 mm thick 6061-T6 aluminum alloy plate was carried out.The corrosion behavior of the weld area was studied by immersion corrosion test and electrochemical corrosion test,and the microstructure of the joint was investigated by using optical microscopy and TEM.The results show that the grain in FSW nugget area of 6061 aluminum alloy is significantly refined,and the content of the second phase at grain boundary is small;the resistance to exfoliation corrosion and intergranular corrosion of the nugget area is better than that of heat affected zone.Compared with the heat affected zone,the nugget zone has higher corrosion potential and lower corrosion current density,which shows better corrosion resistance.