Thermal gradients and associated stresses are critical in designing with ceramic composites having low thermal conductivity. In order to reduce the stresses from thermal gradients, compositional gradients are employed in designing of composite structures. This study addresses development of freeze-spray process to fabricate layered ceramic structures with controlled layer thickness and microstructural development. The composites were processed by spraying of ceramic slurries with low binder content and relatively high solids loadings (up to 40 vol%) on a cooled substrate. The frozen parts were freeze-dried and sintered at elevated temperatures. The relationship between microstructural development and thermal expansion behavior of Al2O3 and Y2O3-stabilized ZrO2 functionally graded ceramic composites is discussed.
Q. Fu et al., "Freeze-Spray Processing of Layered Ceramic Composites," Proceedings of the 17th Annual Solid Freeform Fabrication Symposium (2006, Austin, TX), pp. 339 - 348, University of Texas at Austin, Aug 2006.
17th Annual Solid Freeform Fabrication Symposium, SFF 2006 (2006: Aug. 14-16, Austin, TX)
Materials Science and Engineering
Keywords and Phrases
Ceramic Composites; Ceramic Slurries; Cooled Substrate; Freeze-Spray; Low Binder Content; Stresses; Thermal Expansion; Thermal Gradients
Article - Conference proceedings
16 Aug 2006
This work was supported by the Air Force Research Laboratories, Dayton, OH through the Center for Aerospace Manufacturing Technologies (CAMT) at the University of Missouri- Rolla.