Mathematical Modeling of Ni/SiC Co-Deposition in the Presence of a Cationic Dispersant

Abstract

A mathematical model of the incorporation of SiC particles into a co-deposited Ni film on a rotating disk electrode is proposed. The particles are transported to the electrode surface; they then adsorb and are incorporated if the residence time of any individual particle on the electrode is sufficient to be buried by the co-deposited Ni. The rate of incorporation is thus proportional to the residence time, inversely proportional to the burial time, and is proportional to the number density of particles on the surface. These times are influenced by the hydrodynamics, particle size, current density, and concentration of dispersants used to stabilize the particles. The model can describe the effect of a cationic polymer, PEI, on the incorporation rate. SiC incorporation increases with the introduction of PEI due to an increase in the residence time of the particles on the surface. The model can also reasonably predict the SiC incorporation rate as a function of current density, SiC bulk concentration and rotation speed. Finally, the incorporation of nano-SiC particles is compared with micron-sized SiC particles.