Boundary Element Simulation of Galvanic Corrosion of ZL115 Casting Aluminum Alloy and C41500 Naval Brass

The polarization curves of ZL115 cast aluminum alloy and C41500 navy brass were measured by electrochemical experiments. Based on boundary element method, the model of galvanic corrosion between aluminum alloy with damaged surface coating and brass was established and simulated using polarization data as boundary condition. The results show that the liveness of the cast aluminum alloy rose with the increase of electrolyte concentration and its resistance of corrosion decreased. Under the same conditions, the brass changed slightly. Moreover, the increase of electrolyte concentration and film thickness aggravated galvanic corrosion. By contrast, the influence of film thickness is more obvious; the increase of the area ratio of cathode to anode would significantly fortify the local corrosion current at the anode, intensifying the loss of anode. Increasing the distance between cathode and anode would weaken the galvanic corrosion to a certain extent; however, this effect was very limited.