Sintering resistance of suspension plasma sprayed 7YSZ TBC under isothermal and cyclic oxidation. Issue 5 (May 2020)

• Record Type: Journal Article
• Authors: Xiao, Bingjie; Huang, Xiao; Robertson, Taylor; Tang, Zhaolin; Kearsey, Rick
• Is Part Of: Journal of the European Ceramic Society. Volume 40:Issue 5(2020)
• Page Start: 2030
• Page End: 2041
• Publication Date: 2020-05
• Subjects: Thermal barrier coating -- Sintering -- Mechanical properties degradation -- Vertical cracks -- Suspension plasma spray; Ceramic materials -- Periodicals; Composite materials -- Periodicals; Matériaux céramiques -- Périodiques; Composites -- Périodiques; Ceramic materials; Composite materials; Periodicals; Electronic journals; 666.05
• DOI: 10.1016/j.jeurceramsoc.2019.12.046
• Languages: English
• ISSNs: 0955-2219

Abstract

Abstract: This study examines sintering resistance of a thermal barrier coating (TBC), composed of a 7YSZ suspension plasma sprayed (SPS) top coat (TC), an air plasma sprayed (APS) NiCoCrAl bond coat (BC), and an INCONEL 625 substrate, under isothermal and cyclic conditions with a peak temperature of 1080 °C for 400, 800, and 1300 h/cycles. Microstructure, phase composition and microstrain were examined using SEM and XRD. Mechanical properties of fracture toughness, hardness and elastic modulus were obtained using nano-indentation. Samples under cyclic conditions presented faster sintering rate than under isothermal condition due to larger compressive strain and frequent heating and cooling cycles. Faster degradation of mechanical properties due to sintering leads to shorter lifetime of SPS coating under cyclic conditions. Moreover, vertical cracks within SPS coatings reduces compressive stress leading to a greater lifetime as compared to APS coatings exposed to similar conditions.