Analysis of corrosion resistance of lightweight aluminum alloy sheet in the friction-stir joint area

Abstract

In this thesis, 1 mm thick 6061 aluminum alloy plates are connected using a friction stir joining device, and the metallographic structure and corrosion resistance of the friction stir joint area obtained with different process parameters are systematically analyzed. The results show that the core region of the joint is composed of small equiaxed crystals, and the grains in the heat-affected zone are elongated in the direction of stirring flow. The grain sizes of the heat-affected zone is different, and it is a coexistence zone of grains of various sizes. When the rotation speed of the stirring head is 15000 rpm and the forward speed of the stirring head is 300 mm/min, the self-corrosive potential of the connection area is optimized during electrochemical corrosion, and thus the self-corrosion current is the smallest. With this parameter, the joint area has the best corrosion resistance.