Multi-response parametric optimization of squeeze casting process for fabricating Al 6061-SiC composite

Abstract

The current study aims to investigate the effects of process parameters on mechanical and microstructural characteristics of Al 6061-SiC composite fabricated via squeeze casting. Seventeen experiments in total have been conducted according to Box-Behnken experimental design which contained three process parameters (squeeze pressure, melt temperature, and SiC wt.%) while recording the responses including ultimate tensile strength, hardness, and percentage elongation. ANOVA (analysis of variance) was employed to evaluate the significance and prediction capability of mathematical models developed through regression analysis. The results indicate that squeeze pressure, melt temperature, and SiC wt.% significantly affect the responses whereas ductility is drastically reduced at higher concentrations of SiC reinforcement. SEM micrographs of failed test specimen have been found to be indicative of ductile fracture at higher levels of squeeze pressure and melt temperature. The multi-objective optimization problem has been transformed to an equivalent single-objective problem using grey relation analysis. The desirability analysis revealed optimum setting of process parameters which was confirmed to have improved the ultimate tensile strength by 1.61%, hardness by 1.56%, and percentage elongation by 11.11% as compared to the initial setting.