Effect of Electroless Ni Plating Time on the Surface Evolution and Electrochemical Behavior of Al–cBN Composites

Al-based composites have attracted significant attention in the aerospace, automotive, and electronic industries due to their lightweight characteristics, high specific strength, and superior thermal conductivity. Although Al–cBN composites exhibit enhanced mechanical and wear properties, galvanic interactions between the Al matrix and carbon-based reinforcements can accelerate localized corrosion and reduce electrochemical stability in chloride-containing environments. To improve these limitations, Ni coating has been considered an effective surface modification method because of its high corrosion resistance and electrochemical stability. However, investigations on the surface and electrochemical behavior of Ni-coated Al–cBN composites remain limited. In this study, the surface characteristics and electrochemical behavior of Ni-plated Al–cBN composites were systematically investigated. Surface morphology and microstructural evolution were analyzed using FE-SEM, while crystallographic characteristics and phase evolution were examined through XRD analysis. In addition, electrochemical properties were evaluated using OCP and potentiodynamic polarization measurements. The results revealed that the specimen plated for 600 s exhibited a corrosion potential shift from −0.92 V to −0.38 V, together with a significant reduction in corrosion current density, indicating improved electrochemical stability and corrosion resistance due to the formation of a dense Ni coating layer. These results demonstrate that electroless Ni plating is an effective surface modification technique for enhancing the corrosion resistance and electrochemical stability of Al–cBN composites.