Investigating Effect of Zinc Content on the Mechanical and Corrosion Responses of Al6063-SiC Composite

Abstract

Corrosion susceptibility of Al6063-SiC based composites is attracting unceasing concerns among researchers. The motive of this work was to investigate the influence of zinc content on the corrosion resistance and mechanical responses of Al6063-SiC composites. Zinc was incorporated into the composite at 2, 4, 6, 8 and 10% volume fractions using the Two-step stir casting method. Thereafter, mechanical response, optical microscopy and corrosion tests were carried out. The hardness tests revealed a general decrease pattern in the Brinell Hardness Number (BHN) of Al6063-SiC-Zn composite as the percentage of zinc increased. However, the Impact and tensile strengths of Al6063-SiC-Zn composite increased as the volume fraction of Zn increased. The relative enhancement in the mechanical responses of Al6063-SiC-Zn composites can perhaps be attributed to the manifestation of thickened and dense grain lines observed in the micrographs as the concentration of zinc in the composite increased. Corrosion tests in both sulphuric and saline media revealed a good influence of zinc on the composite. Therefore, the choice of zinc alloying element has potential for enhancing corrosion resistance of Al6063-SiC-Zn composites in brine and acid based environments with satisfactory contributions to their mechanical behaviours.