Investigation of the Protection Performance of Mg and Al Coated Copper in High Temperature or Marine Environments

Copper is commonly used in many applications such as electric wires, industrial machinery, boat propellers and heat exchangers. Although Cu is resistant to corrosion in ambient conditions, it is highly susceptible when exposed to harsh environments such as high-temperature air or marine atmospheres. The application of magnesium or aluminum coatings on Cu can efficiently smooth this disadvantage without affecting its primer properties. In the herein investigation, the deposition of these coatings was accomplished by pack cementation, a simple electrochemical technique which can be easily incorporated in the industrial scale. The final coatings were tested under high temperature environments by non-isothermal (dynamic) and isothermal thermogravimetric measurements, and in artificial sea water (3.5 wt.%-NaCl) by electrochemical corrosion. The structure of both coatings was compact with elevated thickness. The oxidation and corrosion measurements revealed that the coated samples had much better performance compared to the uncoated copper coupons. Furthermore, Al coatings were found to have the best performance when exposed in high temperature environment.