Numerical simulation study on the coating damage of aluminum alloy lap joints surface

摘要

Galvanic corrosion will happen when the top coating of aluminum alloy joint-structures which abound in the aircraft damages. The corrosion type of aircraft materials is atmospheric corrosion that is the electrochemical corrosion under the thin layer electrolyte. The electrochemical properties of the materials covered with the 0.5mm thick film by self-made electrochemical measurement device have been researched in this paper. The potential distribution and corrosion rate of lap joints after the coating damaged have been calculated by BEASY. The simulation results show that the closer to the bolts,the greater the current density of aluminum alloy, the faster the corrosion rate; the corrosion rate is closely related to the coating damage area, the smaller the damage area,the bigger the corrosion rate in the region of coating damage.