AVS 65th International Symposium & Exhibition
    Advanced Surface Engineering Division Monday Sessions
       Session SE-MoA

Paper SE-MoA10
Tunable Self-Healing Thermal Barrier Coatings

Monday, October 22, 2018, 4:20 pm, Room 202C

Session: New Challenges and Opportunities in Surface Engineering
Presenter: J.J. Gu, University of North Texas
Authors: S.S. Joshi, University of North Texas
J.J. Gu, University of North Texas
Y.-S. Ho, University of North Texas
B.W. Wei, University of North Texas
T.Y. Hung, University of North Texas
Y.Y. Liu, University of North Texas
N.B. Dahotre, University of North Texas
S.M. Aouadi, University of North Texas
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Oxide ceramics exhibit a wide spectrum of unique properties, but can suffer from unpredictable and often catastrophic crack propagation and fracture, which limits their use in some applications. One possible solution to overcoming this limitation is to leverage the ability of oxides to repair their inherent flaws and cracks, i.e. to self-heal. The aim of the work is to gain new insights into self-healing mechanisms of a subset of ceramic surfaces, namely thermal barrier coatings, in response to thermal stimuli. TBCs are extensively used to protect metallic blades in gas-turbine engines against harsh operating conditions that include elevated temperatures and corrosive environments. Model systems that were investigated include YSZ-Al2O3-SiC and YSZ-Al2O3-TiC laser processed coatings. The healing process occurs when the carbide phase oxidizes and the resulting oxide flows to the crack site and bonds to the YSZ matrix. The formation of the oxide phase was observed using X-Ray diffraction its formation in the crack site was confirmed using cross-section scanning electron microscopy. The optimum process to create a self-healing composite was determined. Finally, the mechansisms responisble for how the self-healing process impacts deformation and failure resistance as well as corrosion resistance at elevated temperatures was investigated.