Examining the Mechanical and Tribological Behavior of Al-Sic Composite Developed by Centrifugal Casting Technique

The increasing interest in functionally graded materials for automobile, military, and aerospace structural applications in recent years is due to its admirable properties such as good resistance to thermal fluctuation, good formability, and good strength. This study investigates the tribological property of aluminum A356 composites reinforced with silicon carbide particles with varied weight-percents and particle sizes fabricated through centrifugal casting technique. Tribological, mechanical, and SEM analyses were carried out on fabricated composite samples, reinforced with SiC p of 7 µ and 15 µ particle sizes, respectively. The results indicated that the insertion of the reinforcement particles in the aluminum matrix improved the microstructural properties of the fabricated composites and enhanced their tribological properties. Furthermore, this study confirms that the size of the reinforcement particles influences the overall properties of aluminium metal matrix composites. Polishing was done using an automatic polishing machine with different microns of diamond suspensions and fumed silica on polishing cloths. The polishing process continued until a mirror-like surface was achieved. The samples' surfaces were further etched using Keller's reagent to reveal adequate details during the microstructural examination. The mechanical properties of hardness, tensile strength, and wear behavior of the FGM cast samples were also investigated. The individual sectioned samples were subjected to a hardness test to determine the effect of the different particle sizes with the varying concentrations of the reinforcement particles along each sample's length on their respective hardness properties. The hardness test was carried out using the LECO ® M-400-H1 hardness testing machine with a load of 100 g and a dwell time of 15 sec. The hardness value for each sample was determined by taking the average values obtained from five indentations on the sample's surface to be examined. The uniquely developed FGAMMC presented in this paper was subjected to tribological analysis using a pin-on-disc Anton Paar tribometer. A stainless steel counterface with a surface roughness of 15 nm, a load of 5 N, a sliding distance of 400 m, and a motor speed of 100 rev/min was used to determine the tribological property of the samples. The samples' worn surfaces were further examined using SEM to investigate the wear tracks formed and the interaction between the counterface material and samples' surface.