Intermediate Scale Production of Ceramics and Ceramic Coatings by EPD

Abstract

The potential for the commercial use of EPD as a manufacturing technique has been established. Rigs and equipment have been designed and constructed for the EPD of ceramic components to a range of geometries including tubes and plates. Components have been produced with uniform thickness up to 3mm, or with varying thickness. Systems have also been operated to produce ceramic coatings on metal substrates including flat foils, tubes, rods and complex shapes. Coatings of ZrO2, cerium gadolinium oxide (CGO), cermet mixtures, (La0.8Sr0.2)0.98Mn oxide (LSM), TiO2 and Al2O3 have all been successfully produced and such layers can be achieved with a deposition time of <2 minutes. Multiplying the number of EPD cells which can be operated simultaneously enables the average deposit time to be reduced to a level where commercial production becomes feasible. Thicker crack-free layers of the above materials up to 150micron have been produced for applications where a robust porous structure is required. XRD, SEM and EDX results have shown that the EPD methods developed for use in these systems are capable of producing layers from binary or ternary mixtures of suspension without segregation within the formed layers.