Electrophoretic Deposition of Alumina and Nickel Oxide Particles

Abstract

Electrophoretic deposition (EPD) of alumina and nickel oxide particles on nickel substrate has been investigated. Pure ethanol and a mixture of ethanol and water were used as solvents. The stability of Al 2O 3 and NiO suspension in two solvents was studied and compared in terms of zeta potential, electrophoretic mobility and conductivity. The influence of different solvents and deposition parameters such as suspension conductivity, applied voltage and time of dep osition on the weight gain and the morphology of deposits were also evaluated. The results demonstrated that mixture of ethanol and water as a solvent appears to be advantageous over pure ethanol for EPD of Al2O 3and NiO from standpoint of a good stability of suspension, a higher electrophoretic mobility and also due to the uniform deposits in terms of microstructures and thicknesses. Studies the relationship between the increase in applied voltage during EPD and the decrease in conductivity, have shown tha t the increase in voltage was completely caused by the decrease in conductivity of suspension.