Study on the initial electrodeposition behavior of Ni–P alloys

The initial electrodeposition behavior of Ni–P alloys on carbon steel has been studied in this paper and was found to be greatly influenced by the morphology of the substrate. Preferred nucleation of Ni–P alloy coatings takes place at the crystal boundaries and the surface of cementite. Preferred nucleation and growth of Ni–P coatings also takes place at pearlite because pearlite contains cementite phase and many crystal boundaries. The coatings exhibit a polycrystalline structure composed of gathering nano-sized grains. With a continued electroplating time prolonged, the grains not only present two-dimensional sideward growth, but also display three-dimensional growth on them to form a new polycrystalline layer.