Preparation of Cu- graphene coating via electroless plating for high mechanical property and corrosive resistance

Abstract In this paper, the copper (Cu) - graphene (Gr) composite coating was prepared successfully by using electroless plating with copper sulfate (CuSO4) as the main salt and sodium hypophosphite (NaH2PO2) as the reducing agent. That is, by adding dispersed graphene oxide (GO) into the electroless bath, GO was reduced to Gr during co-deposition process, and formed the Cu-Gr composite coating. The surface morphologies and microstructures were characterized by using SEM, TEM, Raman, FT-IR, the mechanical properties and corrosion resistance of the coating were also evaluated. The experimental results revealed that: 1) Graphene exhibited a significant effect on the microstructure of the coating, for example, the grain size of the composite coating varied from the concentration of the added GO, and the optimal value 60 mg/L showed that the smallest grain size and the highest compactness. 2) At the optimal GO concentration, the Cu-Gr coating also was of the highest mechanical properties, i.e. the hardness was 4.2 times higher than that of regular pure copper plating, and elastic modulus was increased by 26%. 3) Compared with regular pure Cu plating, the corrosion resistance of the Cu-Gr coating had a significant improvement, i.e. the Ecorr、icorr、corrosion rate (CR) and inhibition efficiency (η) were also optimized at the optimal GO concentration. It is expected that the Cu-Gr coating will have broad application prospects in the fields of electronics industry, marine engineering and military industry.