Nickel aluminum bronze (NAB) alloys are widely used in marine and industrial components due to their high mechanical strength, corrosion resistance, and fatigue performance. However, their service life may be limited by severe tribological degradation such as friction-induced wear, erosion, and cavitation damage. In this study, the surface properties of NAB alloys were enhanced through the fabrication of SiC-reinforced metal matrix composite (MMC) layers using friction stir processing (FSP), a solid-state surface modification technique. Surface composites containing 10%, 30%, and 50% SiC particles were produced via a single-pass FSP operation. The resulting microstructural evolution, microhardness distribution, and tribological performance were systematically investigated. The results showed that the incorporation of SiC particles significantly influenced both hardness and wear behavior of the modified layers. The maximum microhardness reached approximately 460 HV0.5 in the reinforced surface region, while the effective thickness of the strengthened layer was about 3.5 mm. Tribological tests revealed that the 30% SiC composite exhibited the lowest coefficient of friction (≈0.24), whereas the 50% SiC composite showed the highest wear resistance, reducing the wear rate by approximately 56% compared to the base NAB alloy. In addition, empirical quadratic response modeling and multi-objective desirability analysis were employed to quantify the friction–wear trade-off. The optimization results suggested an intermediate reinforcement level of approximately 35–37% SiC as a compromise condition that simultaneously minimizes both friction and wear. These findings demonstrate that friction stir processing provides an effective approach for tailoring the tribological performance of NAB-based surface composites for demanding engineering applications.