Net-shape manufacturing of intricate components of A356/SiCp composite through rapid-prototyping-integrated investment casting

The present study illustrates the manufacturing aspect of cast particulate metal-matrix composite (PMMC) material through rapid-phototyping-integrated investment casting process. The fluidity reduced from base alloy to composite due to increase in viscosity of the melt in the presence of particulate. The manufacturing of complex shape and thin walled components with PMMC material poses a great difficulty due to their poor fluidity. During investment casting, as the mould is preheated and dissipates heat very slowly, particulate composite does not appreciably lose fluidity but optimum preheat ceramic shell temperature must be maintained during pouring. The dimensional variation from pattern to metallic part shows a very minor difference because of proper allowance for the shrinkage of wax and metal, initially added to the solid model. The SiC reinforced composite reached its peak hardness at an aging time of 4 h, whereas the un-reinforced A356 alloy reached its peak hardness at 10 h of aging.