Corrosion Behavior of New Tin-Brass Alloys with Slightly Different Zn Content in Salt Spray Environment

In general, the produced brass alloys considered to be eligible in the industry usually have a Zn compositional range. However, up to now, there are few reports about the influence of tiny differences of the Zn component of brass on corrosion behavior. In the present study, a series of new tin-brass alloys (CuZnSnAlNiAsBRE) with different Zn contents in the 27 wt% to 30 wt% range were designed and their corrosion behavior in a salt spray environment was investigated. The corrosion behavior was characterized using mass loss, electrochemical impedance spectroscopy, polarization curves, and surface morphology observation, with exposures lasting up to 360 h. With increasing exposure time, the mass loss increased but the corrosion rate decreased. Corrosion rates of the alloys containing 28.3 wt%Zn to 28.8 wt%Zn were lower than those of the other alloys. The corrosion products were a mixture of ZnO, SnO₂, CuCl, CuCl₂, CuO, Cu₂O, and Cu(OH)₂. The present study clearly demonstrated that tiny differences in Zn content have an obvious influence on corrosion resistance. The investigated brass alloys containing 28.3 wt%Zn to 28.8 wt%Zn were found to have a better corrosion resistance in a salt spray environment.