Applicability of Carbonized Coconut Shell and Silicon Carbide Nanoparticles in the Synthesis of Hybrid Aluminium Matrix Composites

The synthesis of agro-waste reinforced metal matrix composites is now very common among researchers because of their cost effectiveness, excellent properties and wide industrial applications. This study synthesized a hybrid aluminium 6061 matrix composite with particulates of silicon carbide, SiC_p and carbonized coconut shell, CCS_P as reinforcement combined in the ratio 1:1, determined the effect of combining SiC_p and CCS_p reinforcements of different sizes and weight fractions on the density, hardness, strength properties and microstructure of the developed composite. The hybrid aluminium matrix composites were developed using the stir casting method. Several samples of the composites consisting of AA6061 alloy with 3, 6, 9, 12 and 15% by wt. each of each of the combined CCSp and SiC_p with different particle sizes were produced and characterized. Also, mathematical models were proposed for predicticting hardness and tensile strength of the nano-composite and validated by comparison with results of the physical experiment and those of other authors.  The results obtained showed that addition of CCSp and SiCp reinforcement to the alloy decreased its density but increased the hardness and tensile strength of the composite. The nano-particulates reinforced composite presented maximum improvement in hardness and ultimate tensile strength values and decreased density value. The microstructures of the developed composite materials revealed uniform distribution of reinforcing particles in the base matrix and excellent bonding between the base matrix and reinforcements after casting. The proposed models were in excellent agreement with experimental data. The developed composite should be suitable for high strength/light weight applications required in the automobile and aerospace industries.

Citation: Michael N. Nwigboa and Lasisi E. Umorub  (2022) Applicability of Carbonized Coconut Shell and Silicon Carbide Nanoparticles in the Synthesis of Hybrid Aluminium Matrix Composites, European Journal of Material Science , Vol.9, No.1, pp.1-17

Keywords: AA6061 alloy; stir casting; metal matrix composites; reinforcements; microstructure, nanoparticles