Interface engineering in oxide/oxide composites
November 5-9, 2017
Oxide fiber/oxide matrix composites are of interest because of their inherent high-temperature oxidation resistance. Specifically, we seek long-term, oxidation resistance at high-temperatures and damage tolerant materials. An undesirable feature of oxide/oxide composites is the reactivity between the oxide fiber and oxide matrix. This reaction may prevent the composite from developing a suitable interface necessary to achieve a high damage tolerance. To achieve a suitable interface, an interphase material is used, i.e., the interface is engineered. Among the oxide interphase materials that have been tried are SnO2, LaPO4, and ZrO2. Porous oxide matrix as well as fugitive coatings have also been tried. All of these have the distinct characteristic that they do not react with alumina. We have also tried a novel interphase material, namely, BaZrO3. Alumina and BaZrO3 do react, but form reaction products in situ during the high temperature processing with sharp and distinct interfaces. These interfaces allow crack deflection to occur; resulting in a damage tolerant behavior in alumina-based composites.
K.K. Chawla, "Interface engineering in oxide/oxide composites" in "Advanced Ceramic Matrix Composites: Science and Technology of Materials, Design, Applications, Performance and Integration", Yutaka Kagawa, Tokyo University of Technology, Japan Dongming Zhu, NASA Glenn Research Center, USA Ram Darolia, GE Aviation (retired), USA Rishi Raj, University of Colorado, Boulder, USA Eds, ECI Symposium Series, (2017). http://dc.engconfintl.org/acmc/44