Effect of process parameters on micro hardness of Al-Al2O3 composite prepared using an alternative reinforced pattern in fused deposition modelling assisted investment casting

Aluminium matrix composites (AMCs) have numerous applications in manufacturing sector. In the present research work, fused deposition modelling (FDM) assisted investment casting (IC) route has been explored for the development of Al-Al2O3 based functionally graded material. Initially, two alternative FDM filaments consisting of nylon-6, Al and Al2O3 (in different proportions) were fabricated on single screw extruder. These filaments were further used to prepare reinforced FDM patterns (which were barrel finished) for IC process. Taguchi L18 orthogonal array has been used to study the effect of processing parameters (like: filament proportion, volume of reinforced FDM pattern, density of FDM pattern, barrel finishing time, barrel finishing media weight and numbers of IC slurry layer) on micro hardness (MH) of Al-Al2O3 composites. Analysis of variance has been used to study the percentage contribution of input parameters and their significance effect on MH. The results of the study highlighted that density of FDM pattern and numbers of IC slurry layer have contributed around 80% for MH. Micro-structural analysis carried out on castings has justified the MH data.