Mechanism of adhesion failure of anodised coatings on 7075 aluminium alloy

摘要

Components manufactured from 7075 aluminium alloy are used particularly by the aerospace industry because of their high strength. Anodising is often used for corrosion protection. However, adhesion failure of the anodising is occasionally observed if the anodised components are subjected to heat. A failure mechanism to explain why anodised coatings on extruded 7075 aluminium sometimes blister following heating has been determined. A variation in the density and location of rows of intermetallic compounds is shown to be a major contributory factor to failure.