Experimental analysis, predictive modelling and optimization of some physical and mechanical properties of aluminium 6063 alloy based composites reinforced with corn cob ash.

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

The Potential of Biomass in Africa and the Debate on Its Carbon Neutrality

To enhance the energy security and promote energy diversity, biomass sources of energy are viable resources worldwide. Bioenergy is an organic source of power derived from various feedstock including fuel wood, energy crops, solid wastes, and residues of plants. This book chapter explores the use of biomass in Africa and the technical and economic potential of these resources for energy supply in the continent. Findings of literature revealed that the potential of biomass is high in Africa due to availability of land, its preference due to limited electricity supply and the exorbitant nature of fossil fuels, the assorted variety of energy crops suitable for growth in the continent and the green nature associated with the resource. The chapter also established that bioenergy is renewable and not carbon neutral. As such, accurate computation of its resultant greenhouse gas emissions based on their sequestration and emission rates is strongly advised to optimize biomass for energy utility and sustainability compared to conventional energy sources

Squeeze Casting Process: Trends and Opportunities

This chapter introduces the importance of casting process, particularly in ferrous foundries. It opens with a high level functional classification of casting processes, with focus on squeeze casting, and its application in the design of metal matrix composites. To lay a suitable foundation on the subject, detailed discussions on the process parameters, process sequence, cost effectiveness, factors governing the selection of the process, associated casting defects, merits and demerits of the process are included. Special emphasis is given to discussions on the casting defects remedial measures and casting quality, types of squeeze casting processes, differences between them, area of application and components that can be manufactured using squeeze casting. The chapter closes with a brief discussion on the future trends and opportunities for improving the squeeze casting process