Influence of Ni–Cu–P Deposits on the Surface Characteristics of Anodized Al, Al2014 and Al7075

Abstract

Abstract Nickel-copper-phosphorous layers were electro-less deposited on the surface of anodized aluminum and aluminum alloys. The electrochemical behavior of the improved surface was investigated in 0.5 M Na2SO4. The corrosion resistance of the modified alloy's surface is ten folds that measured on the anodized materials. The surface morphology was examined by scanning electron microscopy, SCE, and the deposit composition was subjected to x-ray energy dispersive analysis, EDAX. The experimental impedance data were fitted to theoretical data according to a proposed equivalent circuit model. The results show that the Ni–Cu–P layer was deposited homogeneously on the anodized Al surface but on the anodized-alloy surface the layer had a defective nature.