YAG thermal barrier coatings deposited by suspension and solution precursor thermal spray

Owoseni, T. A.; Rincon Romero, A.; Pala, Z.; Venturi, F.; Lester, E. H.; Grant, D. M.; Hussain, T.

Abstract

Yttrium aluminium garnet (YAG) is a promising topcoat material for thermal barrier coatings due to its high temperature stability and better CMAS (calcium-magnesium-alumino-silicate) resistance. YAG topcoats were deposited by suspension and solution precursor high-velocity oxy-fuel (HVOF) thermal spray. The relationships between processing, microstructure and final properties were studied through a range of characterization techniques and thermal cycling tests. The microstructure of the as-sprayed YAG topcoat from stoichiometric solution precursor (SP-YAG) had distributed pores and inter-splat boundaries, while the as-sprayed topcoat produced from suspension (S-YAG) had vertical and branched micro cracks, pores, and inter-splat boundaries. Both as-sprayed coatings were composed of amorphous phase, hexagonal yttrium aluminium perovskite (YAP) and cubic YAG. In thermal cycling tests, 20% of SP-YAG failure was reached after the 10th cycle; whereas, S-YAG reached the failure criteria between the 60th and 70th cycle. The failure of both the SP-YAG and the S-YAG topcoats occurred due to thermal stresses during the thermal cycling.

Citation

Owoseni, T. A., Rincon Romero, A., Pala, Z., Venturi, F., Lester, E. H., Grant, D. M., & Hussain, T. (2021). YAG thermal barrier coatings deposited by suspension and solution precursor thermal spray. Ceramics International, 47(17), 23803-23813. https://doi.org/10.1016/j.ceramint.2021.05.087

• Journal Article Type: Article
• Acceptance Date: May 11, 2021
• Online Publication Date: May 13, 2021
• Publication Date: Sep 1, 2021
• Deposit Date: May 24, 2021
• Publicly Available Date: May 24, 2021
• Journal: Ceramics International
• Print ISSN: 0272-8842
• Electronic ISSN: 1873-3956
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 47
• Issue: 17
• Pages: 23803-23813
• DOI: https://doi.org/10.1016/j.ceramint.2021.05.087
• Keywords: Process Chemistry and Technology; Materials Chemistry; Electronic, Optical and Magnetic Materials; Surfaces, Coatings and Films; Ceramics and Composites
• Public URL: https://nottingham-repository.worktribe.com/output/5569955
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0272884221014735