The Effect of Production Process Parameters on the Tensile Strength of Squeeze Cast Al₂O₃+SiC/Al6061 Hybrid Composites

This study investigated the conditions for the optimal performance of hybrid aluminum matrix composites produced by squeeze casting. The significant die casting parameters chosen for analysis were the squeeze pressure (50, 70, 90 MPa); die preheat temperature (100, 200, 300°C) and duration of pressurization (15, 30, 45 s). Composites containing 10 and 20 % volume fractions of reinforcements were synthesized by infiltrating molten aluminum alloy 6061 into prefabricated porous preforms composed of Al₂O₃+SiC microparticles. Experiments were conducted by implementing the L₉3³ orthogonal design of Taguchi, where the objective function was to maximize the tensile strength of the castings by appropriate statistical analysis. The results suggested that the production process was successful as the microparticles were evenly distributed within the matrix alloy. The control parameters of squeeze pressure and duration of pressurization were found to be the most significant factors influencing the tensile strength of the castings. As the volume fraction of reinforcements increases in the composites, the duration of pressurization is the most critical factor to enhance the tensile strength. The optimal control settings required to maximize tensile strength were specified with respect to the volume fraction of reinforcements content. The data from statistical experimental design was compared with mathematical predictions and through verification tests, these results were found to be in close agreement.