Investigation of Corrosion Resistance of Electroless Nickel Composite Coating Using SiC Nano-Particles

Electroless method is regarded as one of the most efficient coating methods because it is proper coating ability even for complex shapes and edges. We can use different metals for coating in the electroless method, but nickel phosphor has been widely used because of its unique characteristics. The latest researches on electroless nickel phosphor have been focused on simultaneous deposition of solid particles during the coating process. Composite coatings are classified as new materials with proper hardness and wear characteristics, while there is not enough information available about their resistance against corrosion. Hard particles cause resistance against corrosion and increase solidity of coatings among which SiC is the best compound and is more practical than others. In this study, we apply electroless nickel and Ni-P-SiC composite coatings on some samples of ST37 steel. Corrosion resistance of Ni-P coating and Ni-P-Sic nano-composite are examined and compared by use of polarization and impedance measurement experiments. The experimental results show that both Ni-P and Ni-P-SiC have much better corrosion resistance compared to the base metal