Evaluation of particle size distribution, mechanical properties, microstructure and electrochemical studies of AA1050/fly ash metal matrix composite

The mechanical properties and corrosion studies of AA 1050 metal matrix composite reinforced with varying weight fractions of fly ash were investigated. The fly ash weight fractions selected for this study were 2.5 wt%, 5 wt%, 7.5 wt%, and 10 wt%. This research was undertaken to investigate the effect of fly ash particulates on cast AA 1050 matrix composite. The cast samples’ microstructural analysis showed uniform dispersion of the fly ash particles in the 7.5 wt% samples and fairly uniform distribution of the fly ash particles in both the 2.5 wt% and 5 wt% samples. The investigation into the mechanical properties of the samples showed that the ultimate tensile strengths were 75.94 Mpa, 86.35 Mpa, 89.75 Mpa, 92.5 Mpa, and 86.14 Mpa for the base metal, 2.5 wt%, 5 wt%, 7.5 wt%, and 10 wt% composites, respectively. The microhardness analysis revealed an increase in the microhardness values, which was highest for the 7.5 wt% sample. The corrosion studies showed that the corrosion rate was 0.039 mm/yr, 0.013 mm/yr, 0.071 mm/yr, 0.021 mm/yr, 0.051 mm/yr for the base metal, 2.5 wt%, 5 wt%, 7.5 wt%, and 10 wt% composites, respectively. The SEM micrographs revealed pitting as the predominant corrosion mechanism.