Characterization of the corrosion performance of aluminium laser alloyed with stellite-6 and zirconium powders

Light metals have found intense use in the automobile industry, however, the surface properties of aluminium is still unsatisfactory for many purposes. The corrosion performance of aluminium laser alloyed with a combination of zirconium and stellite-6 powders were investigated. Laser surface alloying was carried out using Nd: YAG solid state laser. Characterization of the resultant microstructure was carried out by optical and scanning electron microscopes. Experimental results revealed novel properties due to the microstructure evolved. The addition of these powders to aluminium solid solution retarded the ingress of destructive chloride ions onto the aluminium matrix. This action increased the electrode potential; decreased the anodic activation and promoted the formation of stable passivation on the surface of aluminium. Significant increase in the corrosion performance of the substrate was achieved.