Freeze-spray deposition of layered alumina/zirconia composites

Freeze-spray deposition (FSD) method is described for rapid fabrication of layered composites with controlled layer thickness and uniform microstructure. The graded alumina/zirconia composites are fabricated by FSD of ceramic slurries followed by freeze drying. Aqueous slurries with glycerol addition are sprayed on a cooled substrate using an automated 3D gantry system. Processing parameters such as viscosity of the ceramic slurries, composition and thickness of deposited layers as well as sintering conditions are investigated to optimize the fabrication process. Microstructural analysis of the fabricated composites revealed uniform and crack-free transitional layers indicating a strong interfacial bonding between the layers.