Understanding the Sintering Behavior and its Effect on the Thermal Conductivity of YSZ Coatings for Gas Turbine Applications

Year 2023, Volume: 7 Issue: 2, 204 - 208, 25.07.2023

Garip Erdogan

https://doi.org/10.30518/jav.1312453

Cited By: 1

Abstract

Thermal barrier coatings are essential coatings to protect the combustion chamber liner material from harsh environments in modern gas turbines that are used in aerospace and land-based power generation facilities. As there are several different materials to produce thermal barrier coatings, the conventional thermal barrier coating is yttria stabilized zirconia (YSZ). The most common method to manufacture YSZ coating is plasma spraying method due to its flexibility and rapid production capacity. Using plasma spraying, often requires understanding the process parameters effect on the coating structure. As there are many parameters to control coating process the main outcome of all parameters is the particle temperature and velocity during the spraying process hence the coating properties such as hardness, porosity ratio and deposition rates. Furthermore, not only produced microstructure but also during the service conditions sintering behaviour also be considered. Sintering behaviour of thermal barrier coatings results declining of their thermal insulation properties. Therefore, in this study we have evaluated sintering effect of on the thermal conductivity of the plasma sprayed yttria stabilized zirconia coatings. To achieve this objective, we produced free-standing coatings and subjected them to heat treatment, followed by measurements of their thermal conductivities. The results of this study will contribute to a better understanding of the sintering behaviour and its impact on the thermal performance of thermal barrier coatings.

Keywords

Thermal Barrier Coatings, Plasma Spray, Thermal Conductivity, Sintering, Gas Turbine

References

• Bansal, N. P., & Zhu, D. (2007). Effects of doping on thermal conductivity of pyrochlore oxides for advanced thermal barrier coatings. Materials Science and Engineering: A, 459(1–2), 192–195.
• Boyce, M. P. (2012). 11—Materials. In Gas Turbine Engineering Handbook (Fourth Edition) (pp. 493–514). Butterworth-Heinemann.
• Caron, P., & Khan, T. (1999). Evolution of Ni-based superalloys for single crystal gas turbine blade applications. Aerospace Science and Technology, 3(8), 513–523.
• Cipitria, A., Golosnoy, I. O., & Clyne, T. W. (2009). A sintering model for plasma-sprayed zirconia TBCs. Part I: Free-standing coatings. Acta Materialia, 57(4), 980–992.
• Cizek, J., & Khor, K. A. (2012). Role of in-flight temperature and velocity of powder particles on plasma sprayed hydroxyapatite coating characteristics. Surface and Coatings Technology, 206(8–9), 2181–2191.
• Clark III, L. M., & Taylor, R. E. (1975). Radiation loss in the flash method for thermal diffusivity. Journal of Applied Physics, 46(2), 714–719.
• Clarke, D. R., Oechsner, M., & Padture, N. P. (2012). Thermal-barrier coatings for more efficient gas-turbine engines. MRS Bulletin, 37(10), 891–898.
• Clarke, D. R., & Phillpot, S. R. (2005). Thermal barrier coating materials. Materials Today, 8(6), 22–29.
• Coble, R. L. (1963). A Model for Boundary Diffusion Controlled Creep in Polycrystalline Materials. Journal of Applied Physics, 34(6), 1679–1682.
• Deshpande, S. (2013). High Temperature Sintering and Oxidation Behavior in Plasma Sprayed TBCs [Single Splat Studies] Paper 1—Role of Heat Treatment Variations. Journal of Surface Engineered Materials and Advanced Technology, 03(01), 106–115.
• Grady, J. E. (2013). CMC Technology Advancements for Gas Turbine Engine Applications. https://ntrs.nasa.gov/search.jsp?R=20140000458
• Karaoglanli, A. C. (2023). Structure and durability evaluation of blast furnace slag coatings and thermal barrier coatings (TBCs) under high temperature conditions. Surface and Coatings Technology, 452, 129087.
• Ozgurluk, Y., Doleker, K. M., & Karaoglanli, A. C. (2018). Hot corrosion behavior of YSZ, Gd2Zr2O7 and YSZ/Gd2Zr2O7 thermal barrier coatings exposed to molten sulfate and vanadate salt. Applied Surface Science, 438, 96–113.
• Vassen, R., Cao, X., Tietz, F., Basu, D., & Stöver, D. (2000). Zirconates as New Materials for Thermal Barrier Coatings. Journal of the American Ceramic Society, 83(8), 2023–2028.
• Zotov, N., Bartsch, M., & Eggeler, G. (2009). Thermal barrier coating systems—Analysis of nanoindentation curves. Surface and Coatings Technology, 203(14), 2064–2072.