Journal of Aeronautical Engineering

Journal of Aeronautical Engineering

The investigation of change in thermal conductivity of porous coatings during the aging process

Document Type : Original Article

Authors
Esmaeil Poursaeidi 1
MohammadRasoul Javadi Sigaroodi 2
Javad Rahimi 3
mohammadhasan taleghani 4
Amir hosein Fartash 5
Yousef Yousefi 6
Saba noorsina 7
1 Department of Mechanical Engineering, University of Zanjan, Zanjan, Iran, P. O. Box: 45195-313
2 Department of Mechanical Engineering, University of Zanjan, Zanjan,Iran
3 Department of Mechanical Engineering Zanjan University , Zanjan , Iran
4 Department of Mechanical engineering, Tarbiat Modares University, Tehran
5 Department of Mechanical Engineering, University of Zanjan, Zanjan, Iran
6 Department of Mechanical Engineering, The University of Zanjan, Zanjan, Iran
7 Department of Materials, Faculty of Engineering, Zanjan University, Zanjan, Iran
10.22034/joae.2021.139485
Abstract
Exposure of the TBCs layers to high temperatures for a long time causes sintering in the ceramic layer, resulting in changes in the porosity. Since the thermal conductivity of air in the porosity of the layers is much lower than the ceramic material in the coating, a decrease or increase in the percentage of porosity will end up with changes in the conductivity of the layer, which subsequently affect the overall efficiency. In this study, a TBC was first applied to the prepared samples from Inconel738 turbine blades. The samples were subjected to an aging process in the furnace for a specified time. The porosity changes in the ceramic layer of the coating during the aging process were investigated using image processing of the SEM images. The porosity of the images obtained from SEM and thermal conductivity in different porosities were determined by OOF2 and ImageJ software, respectively. To validate the numerical results, temperature distribution on the thermal barrier coatings is obtained by the analytical solution of the Fourier equation. According to the analysis performed on the SEM images gathered from the samples during different aging hours, it is observed that by increasing the aging hours during 48 hours, the percentage of porosity of the whole ceramic layer decreased by 8%. According to the results, by decreasing porosity in the ceramic layer, an increase in thermal conductivity has been observed, followed by an increase in the substrate's temperature and a decrease in the overall performance over time.
Keywords
Thermal barrier coatings
thermal conductivity
Porosity
ImageJ
OOF2
  • Zhou, S. Mukherjee, K. Huang, Y.W. Park, Y. Sohn, Failure characteristics and mechanisms of EB-PVD TBCs with Pt-modified NiAl bond coats, Mater. Sci. Eng. A.63 - 798–106, 2015.

https://doi.org/10.1016/j.msea.2015.03.120.

  • Zhou, B. Zou, L. He, Z. Xu, J. Xu, R. Mu, X. Cao, Hot corrosion behaviour of La2(Zr0.7Ce0.3)2O7 thermal barrier coating ceramics exposed to molten calcium magnesium aluminosilicate at different temperatures, Corros. Sci. 100 - 566–578, 2015. https://doi.org/10.1016/j.corsci.2015.08.031
  • Zhu, D., & Miller, R. A. Thermal conductivity and elastic modulus evolution of thermal barrier coatings under high heat flux conditions. Journal of Thermal Spray Technology, 9. No 2 2000
  • Ziaei-Asl, A., & Ramezanlou, M. T. Effects of thermal barrier coating (TBC) thickness on temperature distribution of gas turbine blade. In Proceedings of the 3rd Conference on Advances in Mechanical Engineering (ICAME), Istanbul, Turkey 2017.
  • Schlichting, K. W., Padture, N. P., & Klemens, P. G. Thermal conductivity of dense and porous yttria-stabilized zirconia. Journal of materials science, 36(12), 2001.
  • Angle, J. P., Wang, Z., Dames, C., & Mecartney, M. L. Comparison of two‐phase thermal conductivity models with experiments on dilute ceramic composites. Journal of the American Ceramic Society, 2013.
  • Arai, Masayuki, Hiroya Ochiai, and Tatsuo Suidzu. "A novel low-thermal-conductivity plasma-sprayed thermal barrier coating controlled by large pores." Surface and Coatings Technology 285 - 120-127, 2016.‏
  • Chen, Dan, et al. "Comparison of thermal insulation capability between conventional and nanostructured plasma sprayed YSZ coating on Ni3Al substrates." Ceramics International 43.5 - 4324-4329, 2017.‏
  • Huang, Yiling, et al. "Effect of different types of pores on thermal conductivity of YSZ thermal barrier coatings." Coatings 9.2 138, 2019.‏
  • Song, Xuemei, et al. "Effect of Microstructure on the Thermal Conductivity of Plasma-Sprayed Al 2 O 3-YSZ Coatings." Journal of Thermal Spray Technology 25.4 - 770-777,2016.‏
  • Torkashvand, Kaveh, Esmaeil Poursaeidi, and Jafar Ghazanfarian. "Experimental and numerical study of thermal conductivity of plasma-sprayed thermal barrier coatings with random distributions of pores." Applied Thermal Engineering 137- 494-503,2018.
  • Sadowski, T., & Golewski, P. Loadings in thermal barrier coatings of jet engine turbine blades: An experimental research and numerical modeling. Springer 2016.
  • Zhong, X., Zhao, H., Zhou, X., Liu, C., Wang, L., Shao, F., ... & Ding, C. Thermal shock behavior of toughened gadolinium zirconate/YSZ double-ceramic-layered thermal barrier coating. Journal of alloys and compounds,2014.
  • (APS),”www.mdpi.com/journal/coatings, vol. 10, pp. 118, 2020.
  • Bäker, M., Rösler, J., & Heinze, G. A parametric study of the stress state of thermal barrier coatings Part II: cooling stresses. Acta Materialia, 2005.
  • Meier, S. M., Nissley, D. M., Sheffler, K. D., & Cruse, T. A. Thermal barrier coating life prediction model development. 1992
  • Klemens, P. G. Thermal conductivity of inhomogeneous materials. International journal of thermophysics.
  • “OOF2; Finite Element Analysis of Microstructures,”Available: https://www.ctcms.nist.gov/oof/oof2/. 2017.
  • Jadhav, A. D., Padture, N. P., Jordan, E. H., Gell, M., Miranzo, P., & Fuller Jr, E. R. Low-thermal-conductivity plasma sprayed thermal barrier coatings with engineered Acta Materialia,2006
  • Pawlowski, P. Fauchais, L. Pawlowski, and P. Fauchais, “hermal transport properties of thermally sprayed coatings Thermal transport properties of thermally sprayed coatings,,” Int. Mater. Rev, vol. 66, 2016.
  • Lima, R. S. Perspectives on Thermal Gradients in Porous ZrO2-7–8 wt.% Y2O3 (YSZ) Thermal Barrier Coatings (TBCs) Manufactured by Air Plasma Spray (APS). Coatings, 2020.
  • Golosnoy, I. O., Tsipas, S. A., & Clyne, T. W. An analytical model for simulation of heat flow in plasma-sprayed thermal barrier coatings. Journal of Thermal Spray Technology, 2005.
  • Bergman, T. L., Incropera, F. P., DeWitt, D. P., & Lavine, A. S. Fundamentals of heat and mass transfer. John Wiley & Sons,2011.
Journal of Aeronautical Engineering
Volume 23, Issue 1
June 2021
Pages 97-108

  • Receive Date 09 September 2021
  • Revise Date 28 September 2021
  • Accept Date 14 October 2021