Electrodeposition of Ni/TiC Nanocomposites in the Presence of a Cationic Dispersant

The effect of a cationic dispersant, polyethyleneimine (PEI) on electrodeposition of nickel/titanium carbide (Ni/TiC) nanocomposites is characterized. Enhancing the dispersion of TiC nanoparticles in the electrolyte and increasing TiC amount and uniformity in the deposit are crucial to get superior mechanical and tribological nanocomposite properties. Therefore, a key challenge in reaching enhanced composites is the optimization of the dispersant concentration that improves the nanoparticle dispersion in the electrolyte and achieves high and uniform TiC incorporation into the deposit without suppressing electrodeposition. It is determined that PEI at a concentration of 125 ppm increases the stability of TiC nanoparticles in the electrolyte and TiC vol% in the deposit significantly without any substantial inhibition on the electrodeposition kinetics. Ni/TiC electrodeposition is also characterized as a function of key parameters such as TiC electrolyte concentration, current density, and rotation speed in the presence of PEI. Higher and more uniform TiC nanoparticle incorporation is attained for the electrolyte containing PEI than the electrolyte with no dispersant for all cases. Uniform nanocomposites with improved hardness is obtained as a result of Ni/TiC electrodeposition in the presence of the cationic dispersant. (C) 2018 The Electrochemical Society.