Effect of hot rolling on microstructures and mechanical properties of SiCp/A356 aluminum matrix composites

This study focuses on the fabrication of SiCp/A356 aluminum matrix composites (AMCs) through stir casting and hot rolling, with the objective of investigating the effects of reduction on microstructural evolution and mechanical properties of SiCp/A356 AMCs. The composites were subjected to hot rolling at 500 °C for varying reduction levels of 30%, 50%, 70%, and 90%. As the reduction increased to 70%, the size of α-Al grains and SiC particle clusters increased. However, further reduction to 90% resulted in the flattening and elongation of α-Al grains, the dispersion of SiC particles into the grains, and a more uniform distribution of SiC particles. The relationship between reduction and SiC particle distribution was established. The ultimate tensile strength (UTS) and yield strength (YS) of SiCp/A356 AMCs showed a gradual increase with increasing reduction. The rolled composite with a 90% reduction exhibited the optimal combination of UTS, YS, and elongation (EL) values. Besides, the strengthening mechanisms were discussed and the dislocation strengthening has a significant contribution to the improvement of YS.