This study presents a finite element method optimization strategy to enhance the solidification of molten aluminum alloy in the high pressure die casting (HPDC) process for the production of bulk metal matrix composites. A computational fluid dynamics approach based on the explicit volume fluid multiphase (EVFM) model was applied in the ANSYS FLUENT software environment to analyze the effect of pressurized melt infiltration and thermal loading on deformation, heat flux variations, and solidification profiles during solidification processing of aluminum alloy composite in a HPDC die of varying thicknesses, ranging from 3–24 mm. The associated turbulence was accounted for by the k-ε model. The solidification mechanisms were characterized for the performance of the optimal die configuration. The results indicate that the resistance to deformation was not significant for die thicknesses within the 5–15 mm range but increases sharply at a constant rate as the die thickness exceeds 15 mm. The heat transfer characteristics for the 15–21-mm die are considered as optimal for controlled melt solidification. The solidification profiles suggested that heat flux variations were most critical for the 3, 6, and 9-mm die thicknesses, while the capacity to dissipate heat at a constant rate was achieved for die thicknesses of 12, 15, and 18 mm. The thermal analysis on the optimal die configuration indicates the conditions under which the formation and growth of microconstituents would occur during the solidification process. The experimental validation suggested that the die thickness of 18–20 mm has the most significant implication for design. The mechanical properties of the hybrid composite were found to vary nonlinearly with applied pressure, while indicating an enhancement for the elastic plastic properties within the range of 70–90 MPa.