Effect of processing parameters on corrosion behaviour of Al reinforced with Ni-40Fe-10Ti alloy fabricated by FSP

Aluminium alloys has been favoured in many applications because of its exciting properties which include light weight and corrosion resistance. However, susceptibility to pitting corrosion and intergranular corrosion (IGC) are some of the drawbacks of aluminium. The surface of aluminium can be modified to improve its corrosion resistance properties. Surface modification is a surface engineering process that is performed to alter the properties of material surface to improve its service life. Friction stir processing (FSP) is a relatively new and an important solid state material surface modification process. In this study, investigation on the influence of FSP processing parameters on the resulting corrosion resistance surface properties of pure commercial aluminium and Ni-40Fe-10Ti surface composite using friction stir processing technique was conducted. The processing parameters that were studied are tool rotational speed and transverse speed, while all other processing parameters were kept constant. The corrosion behaviour was studied using three-electrode electrochemical cell, and the microstructure of the corroded samples was studied using optical microscope (OM). The results showed that the addition of Ni, Fe and Ti caused a decrease in the anodic and cathodic current densities. The set of processing parameters that resulted in the lowest corrosion rate are the rotational speed of 600 rpm and transverse speed of 70 mm/min.