Effect of the microstructure on the properties of Ni–P deposits on heat transfer surface

In the present work Ni–P deposits with various microstructures were prepared on the low carbon steel substrate by adjusting the electroless plating processing parameters. The results of anti-fouling experiments show that Ni–P deposits can greatly inhibit the adhesion of crystallization fouling in comparison with uncoated copper, stainless steel and carbon steel surfaces. The further experiments indicated that the amount of nanocrystalline phase in the Ni–P deposit affects the surface free energy, as well as changing the anti-fouling and corrosion-resistant properties of the deposit. When the phase structure of the Ni–P deposit is almost amorphous phase, the Ni–P deposit exhibits the best anti-fouling and corrosion-resistant properties. The amorphous Ni–P deposit exhibits high corrosion resistance which is attributed to its extreme structure homogeneity without preferential corrosion paths like grain boundaries or other structural defects, and the higher corrosion resistance could ensure this deposit is not easy to form “transitional interface” connecting fouling and matrix.