Volta potential analysis of intermetallics in 7A52 aluminum alloy

Abstract

In order to study the effect of intermaetallics on the corrosion behaviour of 7A52 aluminum alloy, the alloy was characterized by means of SEM-EDS and scanning Kelvin probe force microscopy(SKPFM). The experimental results indicate that there are two different intermetallics:Al-Mn-Fe and Mg₂Si. Both intermetallics exhibite the negative volta potential relative to the matrix indicating an anodic behaviour. Hereby, they are easy to be dissolved and corroded under the erosive environment, and there become the corrosion initiation sites. The Al-Mn-Fe intermetallics show stronger anodic behaviour than those of Mg₂Si intermetalics. It means that Al-Mn-Fe intermetalics are easier to be corroded.

Keywords

intermetallics / volta potential / Al-Mn-Fe / Mg₂Si / 7A52 aluminum alloy

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