Journal of Materials and Engineering Structures (Nov 2020)
Experimental analysis, predictive modelling and optimization of some physical and mechanical properties of aluminium 6063 alloy based composites reinforced with corn cob ash.
Abstract
In the present work, aluminium alloy 6063 reinforced with various weight percentages of corncob ash (CCA) particles (2.5%, 5%, 7.5%, 10%, 12.5% and 15%) were prepared using stir casting process. Some physical and mechanical properties (density, % porosity, hardness, wear index, tensile strength and impact strength) of the produced composite were characterized and compared with that of the matrix alloy. Corncob ash reinforcements were observed to have been distributed homogeneously in the Aluminium Matrix with pockets of reinforcement particles agglomeration. The reinforcement of CCA particles improved the hardness, wear index and the density of the produced composite over that of the base alloy. There was a reduction in the tensile and impact strengths of the composites compared to the unreinforced matrix alloy. Statistical evaluation and optimization using mixture design of the Design-Expert software package (Stat-Ease) revealed the optimal concentrations of the matrix and the reinforcement mixture and their effects on the studied properties of the developed composites. Regression models were developed for predicting and optimizing the various physical and mechanical properties of the composites. Optimization solution indicates that optimal mixture components of 92.081 and 7.919% (matrix and reinforcement wt%) will yield optimal composite properties’ responses. Based on the improved hardness, wear-resistance and low density of the CCA reinforced AA6063 base composites produced could be employed in the production of automotive components requiring lightweight, load-bearing and wear-resistant composites.