Influence of fluorosurfactants on the codeposition of ceramic nanoparticles and the morphology of electroless NiP coatings

Electroless NiP composite coatings with SiC or Si3N4 nanoparticles were prepared from an additive-free bath. Cationic, anionic and non-ionic fluorosurfactants were used to try to avoid the agglomeration and the particle incorporation into the coating. Particle size and zeta potential were used to characterize the dispersion. The drawbacks of measuring these properties at the plating conditions (high ionic strength media and temperature) were discussed. Results indicated that the addition of low concentrations of fluorosurfactants did not modify the zeta potential of the particles in the bath but increased the amount of embedded particles. Moreover, the presence of the fluorosurfactants, mainly the non-ionic one, had a positive effect on the surface roughness and performance of NiP composite coatings.