Electrophoretic deposition—mechanisms, myths and materials

Explanations of the deposition process during electrophoretic deposition (EPD) are presented and their boundary conditions discussed. It is suggested increasing resistance during EPD is due to the deposit and not dilution of current carrying species in the suspension. Dialysis membrane experiments demonstrate ions carry significant current. Side-effects of two suspension-conditioning agents are described, i.e., TMAH and PEI. The former can induce “aging” in suspension as its surface adsorption varies with time and reduces suspension pH. PEI appears to adsorb on all ceramic and metal powders, so may be a universal EPD agent for stoichiometric deposition of ceramic/ceramic and ceramic/metal powder-mixtures. Novel structures produced by EPD are presented.