Alumina and Zirconia Laminar Coating Prepared by Complex Electrolytic Deposition Method

Abstract

The deposition of alumina (nano-powder, <80nm) and zirconia doped with yttria laminar composite coatings on Ni3Al coatings were investigated via a complex method of Sol-Gel, electrolytic deposition (ELD) and electrophoretic deposition (EPD). The average particle sizes of alumina and zirconia are 80nm and 20nm respectively. The relation of deposition parameters (deposition voltage, dwell time) and deposition rate was discussed based on the experiment results of alumina, zirconia single and laminated coatings deposition. The post thermal treatments were performed in attempt to acquire a dense multilayer composite ceramic coating. The uniform duplex or laminar coatings could be achieved via this complex method. The surface and cross-sectional morphologies of two layers and ten layers alumina/ zirconia composite ceramic coating after sintering showed that the laminar structure thickness could be tailored by controlling the deposition voltage and dwell time. The sintering mechanism of nano-sized alumina and zirconia was also discussed.