Evaluation of Cast Al-Si-Fe alloy/Coconut Shell Ash Particulate Composites

Al-7wt%Si-2wt%Fe alloy/Coconut shell ash(CSAp) composites having 3-15wt% coconut shell ash were fabricated by double stir-casting method. The microstructure, hardness values and density of the composites were evaluated. The density of the composites decreased as the percentage of coconut shell ash increases in the aluminum alloy. This means that composites of lower weight component can be produced by adding CSAp. Microstructural analysis showed fairy distribution of coconut shell ash particles in the aluminum alloy. The presence of the coconut shell ash particles in the matrix alloy resulted in a much smaller grain size in the cast composites compared to the matrix alloy as confirmed from X-ray diffractometer analysis. Significant improvement in hardness values is noticeable as the wt% of the coconut shell ash increased in the alloy. Hence, this work has established that incorporation of coconut shell particles in aluminum matrix can lead to the production of low cost aluminum composites with improved hardness values.