Effects of the longitudinal and transversal structural grain morphologies upon the corrosion resistance of zinc and aluminium specimens

Abstract

Several different structural morphologies may develop due to a wide range of the operational conditions that may exist during solidification. It was reported that the structural morphology affects the corrosion resistance. The aim of this study is to investigate the influence of the longitudinal (columnar) and transversal (equiaxed) structures of the same sample upon the corrosion resistance of pure aluminium and zinc castings. In order to obtain both longitudinal and transversal structures a vertical upward solidification apparatus was used. The corrosion resistance was analysed by the EIS and Tafel extrapolation methods in a 3 % NaCl solution. The investigation has shown that both structures present similar corrosion behavior.