The factors of alloying elements on corrosion resistance of aluminum alloys

Abstract

Corrosion resistance is a key property for aluminum alloys used in automotive heat exchangers. This study focuses on comparing two variations of post-brazed 3003-H24 aluminum alloys with 2-sided cladding 4045. One of them is the special developed for corrosion resistance. Another one is the generic and widely commercial used alloy. The specimens were prepared by heating in the brazing furnace at temperature of 600 °C for 5 min in order to let the clad material diffuse into the core layer to create the corrosion protection layer. This study compared the corrosion resistance of two alloys by the car maker’s Cyclic Condenser Corrosion test method (CCCT). The results indicate that the special developed alloy has better corrosion resistance than the generic alloy. According to the corrosion test result, further study was performed in order to explain potential factors that make the difference between two alloys. The results were discussed in terms of chemical composition, mechanical properties, microstructure and corrosion potential. It was observed that the difference of Fe content in the core layer of the alloys yields highly impact on the corrosion resistance.