Experimental investigation of corrosion behaviour in Al alloy reinforced with SiC functionally graded composite

The corrosion behavior of Al6061 alloy reinforced with 10 wt.% Silicon Carbide (SiC) particles in a Functionally Graded Composite (FGC) that was produced using vertical centrifugal casting and stir casting techniques is the primary focus of this investigation. The microstructural analysis demonstrated a distinct gradient in the distribution of ceramic particles, which led to low, intermediate, and high particle concentration zones throughout the cross section. The highest hardness was confirmed in the high particulate concentration zone by Vickers microhardness testing, which was attributed to enhanced ceramic dispersion. The corrosion performance of a Taguchi L9 orthogonal array was assessed in acidic media, including hydrochloric acid (HCl), sulphuric acid (H₂SO₄), and nitric acid (HNO₃), at varying plunging durations and distances from the boundary edge. The results indicate that the Corrosion Rate (CR) was significantly influenced by the acid type and plunging durations. The CR was at its highest in HCl and decreased as the immersion duration increased as a result of the formation of passive layers. The CR increased as the distance from the boundary margin increased, as a result of the weaker development of passive layers in the inner areas and the lower ceramic content.