iTSSe TSS ADVANCED MATERIALS & PROCESSES | APRIL 2025 39 iTSSe TSS FEATURE 8 type of 8 wt% YSZ TBC at the upper end of reported values for APS-applied TBCs of similar thickness and porosity levels[8]. Failure analysis provided further insights into the performance of the coatings. Cohesive failure was observed within the YSZ topcoat, while adhesive failure occurred at the interface between the YSZ and the bond coat. Importantly, the bond coat consistently adhered to the substrate, highlighting the reliability of the torch in producing coatings with robust adhesion properties. The results confirm that Portech’s APS 3MB-PT-ID torch is capable of delivering coatings with comparable performance to those produced by conventional 3MB torches in outer diameter environments, while also offering the unique capability of operating in confined geometries (Fig. 3). This innovation addresses a critical gap in the field of thermal spray coatings and opens new possibilities for protecting components in challenging environments. The compact design, long bore depth capacity, and advanced heat protection system, combined with compatibility with existing control consoles and robot mounting, make it an exceptional tool for manufacturing current and next-gen TBCs in the confined geometries of gas turbine engine components. ~iTSSe Acknowledgment The results presented in this case study were achieved at the National Research Council of Canada (NRC), and the authors extend their sincere gratitude to Dr. Rogerio Lima, FASM, for his invaluable support and insights throughout this research. For more information: Ehsan Alirezaei, supply chain lead, Portech Ltd., 195 Clearview Ave., Ottawa, ON K1Z 6S1, Canada, +1 613.263.2630, ehsan.alirezaei@portech-co.ca, hossein.shahbazi@portech-co.ca, portech-co.ca. References 1. H. Shahbazi, et al., Optimization of HVAF Process Parameters for Enhancing FeCoNiCrAl HEA Bond Coatings in Thermal Barrier Systems, J. Therm. Spray Technol., 2025, doi.org/10.1007/s11666-024-01919-9. 2. H. Shahbazi, et al., Enhancing the Optimized HEA Bond Coating in TBC Systems via HVAF Technique, Thermal Spray 2024: Proceedings from the International Thermal Spray Conference, ASM International, p 594–610, 2024. 3. H. Shahbazi, et al., High Entropy Alloy Bond Coats for Thermal Barrier Coatings: A Review, J. Therm. Spray Technol., 2023, doi.org/10.1007/s11666-023-01701-3. 4. H. Vakilifard, et al., “High Entropy Oxides as Promising Materials for Thermal Barrier Topcoats: A Review,” J. Therm. Spray Technol., p 447–470, 2024. 5. W.R. Chen, et al., TGO Growth Behaviour in TBCs with APS and HVOF Bond Coats, Surf Coat Tech, 202(12), p 2677–2683, 2008. 6. R.S. Lima, B.M.H. Guerreiro, and M. Aghasibeig, Microstructural Characterization and Room-Temperature Erosion Behavior of As-Deposited SPS, EB-PVD and APS YSZ-Based TBCs, J. Therm. Spray Technol., 28(1–2), p 223–232, 2019. 7. A. Feuerstein, et al., Technical and Economical Aspects of Current Thermal Barrier Coating Systems for Gas Turbine Engines by Thermal Spray and EBPVD: A Review, J. Therm. Spray Technol., 17, p 199–213, 2008, doi.org/10.1007/ s11666-007-9148-y. 8. R.S. Lima, Porous APS YSZ TBC Manufactured at High Powder Feed Rate (100 g/min) and Deposition Efficiency (70%): Microstructure, Bond Strength and Thermal Gradients, J. Therm. Spray Technol., 31, p 396–414, 2022, doi.org/10.1007/ s11666-021-01302-y. Fig. 2 — Micrograph showing strong adhesion at all the interfaces between the topcoat, bond coat, and substrate. Fig. 3 — Cross-section of samples coated with the 3MB-PT-ID torch (top) versus those coated using conventional 3MB torch (bottom).
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