Potentially Strong and Tough ZrO2-Based Ceramic Composites ≥1300 °C by Electrophoretic Deposition

Electrophoretic deposition is used to synthesize laminates of YPSZ/Al₂O₃. The technique is shown to result in dense composites with layers as thin as 3 μm. A protocol for tough laminates ≥ 1300°C strong enough to withstand quenching to room temperature is suggested, based on the morphology of natural composites. A thin YPSZ surface layer is strengthened by a subsurface layer of MgO/MgAl₂O₄ followed by a functionally-gradiented 100% Al₂O₃ to 100% PSZ layer. The interior consists of alternate layers of Al₂O₃/YPSZ with La-aluminate at their interfaces. Al₂O₃ fibres with 10 nm of gold on their surface serve as the deposition electrode, resulting in central curved layers of YPSZ and Al₂O₃. Microstructures of the resultant composites are presented and Vickers indentation used to demonstrate crack paths therein.