Electrophoretic Alumina Sol-Gel Coatings on Metallic Substrates

Abstract

Electrophoresis offers a novel method for depositing ceramic coatings onto a variety of substrates. In this work, hydrated alumina, prepared by the sol-gel method, was applied to aluminum alloy substrates. Electrophoretic coating provides two new control variables, voltage and time, to those already provided by simple dip-coating—sol chemistry (pH), sol composition and sol viscosity. The coatings produced are harder, thicker, and more dense than those obtained in dip-coating.