Review—Corrosion-Resistant Metastable Al Alloys: An Overview of Corrosion Mechanisms

Abstract

Commercial aluminum alloys exhibit localized corrosion when exposed to environments containing aggressive anions. Alloying of Al with specific elements (M: Cr, Mo, V, Nb, etc) using non-equilibrium processing techniques has been reported to result in significantly improved corrosion resistance due to the formation of a supersaturated solid solution and uniform distribution of M in the matrix. Several theories describing the corrosion behavior of Al–M alloys have been postulated. This paper presents an overview of the most common non-equilibrium alloying techniques implemented for the production of the metastable Al–M alloys and posited corrosion mechanisms for the improved corrosion resistance.