Simultaneous improvement of mechanical and corrosion properties of aluminum alloys

Abstract

The use of Al-alloys is limited in many applications due to a dramatic deterioration of the corrosion properties with any effort made to increase the strength. The hardening phases, uniformly distributed fine intermetallics, act as electrochemical heterogeneities and promote galvanic interactions, thus causing localized corrosion. The chemical composition, size, number, and distribution of the intermetallics in the matrix govern the corrosion of A1 alloys. Refining the size and doping of intermetallics via microalloying have been found effective in improving corrosion resistance of A1 alloys. This paper presents an overview of recent research on: 1) understanding the influence of intermetallics on corrosion of A1 alloys and methods to optimize corrosion and mechanical properties by controlling intermetallic formation via advanced production and post- Production processing techniques, and 2) development of ultraAhigh strength and corrosion resistant A1 alloys by combining suitable alloying additions and alloy production techniques.