Effect of Synthesis Procedure on Particle Dispersion and Hardness of Al–SiC Functionally Graded Metal Matrix Composite

Abstract

Fabrication of Functionally Graded Metal Matrix Composites (FGMMC) especially with high ceramic reinforcement’s volume fraction is highly challenging. Depending on the processing technique and process parameters various defects may arise. This research aims to find the best procedure to make FGMMCs with the highest quality and minimum cost. A new method is proposed that incorporates lost-foam and melt infiltration with semicentrifugal casting to produce FGMMC. Experiments were performed to in-situ fabricate 6061-Aluminum alloy reinforced with gradient distributed Silicon carbide particles (Al/SiC FGMMC). Effect of SiC %, Al pouring temperature, and rotational speed on the fabricated specimens’ hardness, strength, and reinforcement gradient were investigated using the design of experiments and regression analysis. Results reveal the optimum procedure and process settings based on desired properties/gradient required. Mathematical model formulated captures the effect of these process parameters on process cost, and cost of poor quality. Improper selection of these parameters may lead to extensive losses due cost of poor quality which is 12 times higher than the material cost. The proposed manufacturing process proved satisfactory in ensuring proper dispersion. A desirability function can be used to determine the process parameters and volume fraction that minimizes the defects and gives superior properties for a specific application.