Compatibility of Ni-P Coating with Cathodic Protection of Mn-Al Bronze

Ni-P coating was prepared on the surface of Mn-Al bronze by chemical-plating method. The morphology and composition of Ni-P coating were studied by SEM and EDAX. The effects of cathodic polarization potential on the coating and deposit film were investigated. The compatibility of Ni-P coating with cathodic protection of Mn-Al bronze was discussed. The results showed that the current for the same polarization potential decreased by coating. The main composition of the deposit film was CaCO3. The deposit layer formed more rapidly and finer at more negative potentials. There was no adverse effect of cathodic polarization on Ni-P coating when the protective potential range was from -0.85 V to -1.05 V(CSE). Ni-P coating and cathodic protection of Mn-Al bronze exhibited good compatibility.