Fabrication and performance of carbon-sol-reinforced Cu composite coatings

• Carbon-sol-reinforced Cu composite coatings were successfully fabricated via electrodeposition, achieving uniform dispersion of carbon particles and enhanced coating quality. • The optimal addition of 20 mL/L carbon sol significantly improved coating thickness, density, and uniformity, leading to superior wear and corrosion resistance. • The Cu-CS composite coating exhibited a low wear volume (1.15 × 10−3 mm3), high hardness (HV0.5 137.1), and low corrosion rate (0.191 mm/a), attributed to strengthening and lubricating effects of carbon particles. • Excessive carbon sol content compromises the microstructure, creating defects that undermine coating performance, highlighting the importance of optimizing reinforcement concentration.