Growth selection induced residual stresses and fracture behavior of as-deposited thermal barrier coatingsShow others and affiliations
2024 (English)In: Journal of The American Ceramic Society, ISSN 0002-7820, E-ISSN 1551-2916, Vol. 107, no 12, p. 8459-8473Article in journal (Refereed) Published
Abstract [en]
This study explored the impact of microstructure and residual stresses on the fracture behavior of as-deposited thermal barrier coatings (TBCs). Two distinct air plasma sprayed TBCs, Coating A (conventional lamellar porous) and Coating B (dense vertically cracked), were investigated. Coating A involved coarser but less dense powders as feedstock and a lower substrate temperature during deposition. Further, Coating A had (Formula presented.) times higher randomly oriented porosities, finer grains, lower hardness, and elastic stiffness. Strikingly, however, the fracture strength was higher for the porous as-deposited Coating A. The answer to this apparent contradiction emerged from the intergranular residual stresses. These were measured using both X-ray diffraction and high-resolution-electron backscattered diffraction. Coating B, deposited at a higher substrate temperature, had clear growth selection of (Formula presented.) oriented grains. These also had more out-of-plane normal and shear residual stresses. The growth selection induced residual stresses appeared responsible for the decohesion of Coating B from the substrate and, correspondingly, lower fracture strength. © 2024 The American Ceramic Society.
Place, publisher, year, edition, pages
John Wiley and Sons Inc , 2024. Vol. 107, no 12, p. 8459-8473
Keywords [en]
Fracture mechanics; Plasma spraying; Powder coatings; Sprayed coatings; Air plasma sprayed thermal barrier coatings; Barrier coatings; Elastic stiffness; Finer grains; Fracture behavior; Growth selection; Low hardness; Low substrate temperature; Stress behavior; Thermal barrier; Thermal barrier coatings
National Category
Manufacturing, Surface and Joining Technology
Research subject
Production Technology
Identifiers
URN: urn:nbn:se:hv:diva-22384DOI: 10.1111/jace.20070ISI: 001292433900001Scopus ID: 2-s2.0-85201425666OAI: oai:DiVA.org:hv-22384DiVA, id: diva2:1927683
2025-01-152025-01-152026-03-31Bibliographically approved