Fracture performance and crack growth prediction of SPS TBCs in isothermal experiments by crack numbering density. Issue 3 (15th February 2020)

• Record Type: Journal Article
• Authors: Xiao, Bingjie; Robertson, Taylor; Huang, Xiao; Kearsey, Rick
• Is Part Of: Ceramics international. Volume 46:Issue 3(2020)
• Page Start: 2682
• Page End: 2692
• Publication Date: 2020-02-15
• Subjects: Thermal barrier coating -- Crack numerical density -- Fracture -- Gamma statistics; Ceramics -- Periodicals; Céramique industrielle -- Périodiques; Ceramics; Periodicals; Electronic journals; 666
• DOI: 10.1016/j.ceramint.2019.09.258
• Languages: English
• ISSNs: 0272-8842

Abstract

Abstract: This study examined the application of crack numerical density theory (CND) to determine the damage state of a thermal barrier coating (TBC) produced using the suspension plasma spray (SPS) technique. A TBC consisting of a partially stabilized zirconia topcoat was deposited upon an APS NiCoCrAl bondcoat and INCONEL 625 substrate. The TBC was exposed to an isothermal temperature of 1080 °C for a duration of up to 1300 h with specimens removed for examination at, 400 h, 800 h and 1300 h. Material properties after each exposure were determined and utilized to fit a CND model to predict the crack distribution within the topcoat following isothermal exposure. Probabilities of cracks developing within the topcoat that can bridge asperities (0.01% at 400 h, 2% at 800 h, and 11% at 1300 h) were determined indicating that CND may be a useful tool for predicting lifetimes of SPS-TBCs.