A Numerical Study on Generation Mechanism of Vertical Cracks in Top Coat of TBCs During APS Deposition

• Published in: Journal of thermal spray technology Vol. 24; no. 5; pp. 730 - 738
• Main Authors: Ito, K., Kuriki, H., Enoki, M.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-06-2015
• Subjects: Analytical Chemistry; Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Machines; Manufacturing; Materials Science; Peer Reviewed; Processes; Surfaces and Interfaces; Thin Films; Tribology; accoustic emission; in situ monitoring; finite element modeling; thermal stress; heat transfer; segmented coatings; fracture
• ISSN: 1059-9630; 1544-1016
• DOI: 10.1007/s11666-015-0232-4

Clarification of crack generation mechanism in the top coat of the thermal barrier coatings (TBCs) during atmospheric plasma spray process is important to improve the reliability of TBC. In this study, finite element analyses of stress and strain during the deposition process were conducted with layer-by-layer method to understand the cracking behaviors. Stress relaxation by generation of vertical cracks was expressed as an elasto-plastic behavior of the coating. The effects of pre-heating temperature of the substrate and plasma power on crack development were analyzed by changing of the initial and atmospheric temperatures in simulation, respectively. The simulation results of radial strain explained the experimental results of crack monitoring by non-contact laser acoustic emission method.