Influence of Silicon Nitride on the Electrochemical Corrosion Features of Functionally Graded Aluminium Composite

Abstract

Functionally Graded Composites (FGCs) represent an evolving category of engineering materials distinguished by their property variations along a designated direction, specifically designed to fulfill targeted applications. This study involved the fabrication of Al (Aluminium) A356 alloy strengthened with Silicon Nitride (Si₃N₄) FGC using a vertical centrifugal casting technique. The optical microscope, X-ray Diffraction (XRD), and Vicker’s microhardness evaluator examined the gradient dissemination of Si₃N₄ ceramic particles. An electrochemical corrosion study was conducted on various regions of the FGC utilizing a potentiostat, examining the heat-treated situation in comparison to the as-cast situation. Under heat-treated situations, the ceramic concentrated zone exhibited the smallest Corrosion Rate (CR) of 0.0109 mmpy, representing a reduction of 75% compared to the 0.0439 mmpy observed in the matrix concentrated zone under as-cast conditions. Additionally, the Si₃N₄ particles functioned as a protective barrier within the ceramic concentrated zone, decreasing CRs compared to further regions