This study explores the advantages, corrosion resistance, and mechanical performance of dissimilar friction stir welded (DFSW) joints between AA6061 and AA6082 alloys. Combining these alloys offers an optimized balance of strength and corrosion resistance, making them valuable for marine armor applications. By systematically varying SiC content (2 wt.%, 5 wt.%, and 8 wt.%) and processing parameters, the study identifies the optimal conditions for enhancing joint performance. The results demonstrate that incorporating 5 wt.% SiC at 2000 rpm rotational speed and 10 mm/min transverse speed achieves the highest tensile strength of 335 MPa, representing 95% of AA6082’s base strength. This condition also improves strain by 4.5% over AA6082 due to practical grain refinement, controlled SiC dispersion, and minimized particle aggregation. Additionally, this composition enhances dislocation pinning, strengthening the weld without inducing embrittlement. The optimal SiC content promotes smooth material flow, reducing defects such as voids and ensuring superior weld integrity. In contrast, the lowest strength of 300 MPa occurs at 8 wt.% SiC, 1000 rpm, and 30 mm/min, with a 6.25% reduction in stress. The excessive SiC content in this condition leads to particle clustering and increased brittleness. Furthermore, corrosion resistance improves at 5 wt.% SiC, with a 35% reduction in weight loss compared to the 2 wt.% and 8 wt.% SiC conditions. These findings highlight the critical role of SiC content and processing parameters in optimizing DFSW joints for high-performance applications, offering a balanced approach to strength, ductility, and corrosion resistance.