Developments in Processing of Ceramic Top Coats of EB-PVD Thermal Barrier Coatings


Article Preview

Partially Yttria Stabilized Zirconia (PYSZ) based Thermal Barrier Coatings (TBC) manufactured by EB-PVD process are a crucial part of a system, which protects the turbine blades situated at the high pressure sector of aero engines and stationary gas turbines under severe service conditions. These materials show a high strain tolerance relying on their unique coating morphology, which is represented by weakly bonded columns. The porosity present in ceramic top coats affects the thermal conductivity by reducing the cross sectional area through which the heat flows. The increase in thermal conductivity after heat-treatment relates to the alteration of the shape of the pores rather than the reduction of their surface-area at the cross section. The studies carried out by the authors demonstrate that the variation of the parameters during the EB-PVD processing of PYSZ based top-coats alters the columnar morphology of the coatings. Consequently, these morphological changes affect primarily the thermal conductivity and eventually the Young’ Modulus which are the key physical properties of this material group. New ceramic compositions covering zirconia coatings stabilized with alternative oxides, pyrochlores and hexaluminates are addressed. Failures occurring in ceramic top coats mark the lifetime of TBC system and therefore, it is necessary that their performance should go beyond that of the-state-of-the-art materials. This context summarizes the research and developments devoted to future generation ceramic top coats of EB-PVD TBCs.



Edited by:

Marc Anglada et al.




B. Saruhan et al., "Developments in Processing of Ceramic Top Coats of EB-PVD Thermal Barrier Coatings", Key Engineering Materials, Vol. 333, pp. 137-146, 2007

Online since:

March 2007




[1] D. D. Hass, A. J. Slifka, and H. N. G. Wadley, Acta Mater., 49, 973-83 (2001).

[2] J. R. Nicholls, K. J. Lawson, A. Johnstone, and D. S. Rickerby, Surface and Coatings Technology, 151-152, 383-91 (2002).

[3] K. Fritscher, F. Szücs, U. Schulz, B. Saruhan, W. A. Kaysser, Ceramic Engineering and Science Proceedings, 23 (4) Part B, 341-352 (2002).

[4] U. Schulz, K. Fritscher, C. Leyens, M. Peters, Ceramic Engineering and Science Proceedings, 12(4) Part B, 347-356 (2001).

[5] E. R. Andrievskaya, L. M. Lopato, J. of Mater. Sci., Vol. 30 (1995), S. 2591-2596.

[6] R. Subramanian, U.S. Pat. No. 6 258 467 B1, Jul. (2001).

[7] M. J. Maloney: U.S. Pat. No. 6 177 200 B1, (2001).

[8] R. Vaßen, X. Cao, F. Tietz, D. Basu, D. Stöver, Journal of the American Ceramic Society, Vol. 83.

[8] (2000), S. 2023-(2028).

[9] R. Gadow and M. Lischka, Surface & Coatings Technology, 151-152 (2002) 392-399.

[10] U. Schulz, J. Münzer, and U. Kaden, Ceramic Engineering and Science Proceedings, 23 (4), 353-360 (2002).

[11] U. Schulz, K. Fritscher, C. Leyens, M. Peters, and W. A. Kaysser, Materialwissenschaft und Werkstofftechnik, 28, 370-76 (1997).


[12] K. Wada, N. Yamaguchi, and H. Matsubara, Science and Coatings Technology, 191 (2005).

[13] S.G. Terry, Evolution of microstructure during the growth of thermal barrier coatings by Electron-Beam Physical Vapor Deposition, Materials Department, Dissertation, University of California, Santa Barbara, 2001, p.197.

[14] D.V. Rigney, et al., U.S. Pat. No. 6 447 854 (2002).

[15] J.M. Nieuwenhuizen, H.B. Haanstra, Philips Techn. Rev. 27, 87 (1966).

[16] K. Fritscher, W. Bunk: Density Graded TBCs Processed by EB-PVD, in: FGM 90, ed. M. Yamanouchi, J. Sendai, FGM Forum, 91-96 (1990).

[17] K.J. Lawson, J.R. Nicholls, D.S. Rickerby: Thermal conductivity and ceramic microstructure, in High temperature surface engineering, ed. D.R.J. Nicholls, D. Allen, The Institute of Materials, London, (1997).

[18] D.L. Youchison, et al., Surface and Coatings Technology 177-178 (2004) 158-164.

[19] W. Beele, G. Marijnissen, E. Vergeldt, Nice, Forum of Technology, 1-7, (2002).

[20] J.R. Nicholls, K. Lawson, A. Johnstone, D. Rickerby, Low Thermal Conductivity EB-PVD TBCs, Materials Science Forum, 369-372 (2001) 595-606.


[21] U. Schulz, K. Fritscher, M. Peters, 82 (1996) 259-269.

[22] U. Schulz, K. Fritscher, M. Peters, J. Eng. Gas Turbines and Power 119 (1997) 917-921.

[23] B.A. Nagaraj, D.J. Wortmann, ASME J. Eng. Gas Turbine Power, 112 (1990) 536.

[24] U. Schulz, K. Fritscher, C. Leyens, Surface and Coatings Technology, 133-134 40-48 (2000).

[25] C. Leyens, U. Schulz, K. Fritscher, Materials at High Temperatures, 20 (2003) 475-480.

[26] U. Schulz, B. Saint-Ramond, O. Lavigne et al., Ceramic Engineering and Science Proceedings, 25(4), (2004) 375-380.

[27] S. Alperine, V. Arnault, O. Lavigne, R. Mevrel, 2001, U.S. Pat. No. 6333118, EP Pat. No. 1085109.

[28] J. Singh, et al., Journal of Materials Science, 39 (2004) 1975-(1985).

[29] K. Matsumoto, Y. Itoh, T. Kameda, Science and Technology of Advanced Materials, 4 (2003) 153.

[30] M. Maloney, 2001, U.S. Pat. No. 6177200, U.S. Pat. No. 617560.

[31] R. Subramanian, 2002, U.S. Pats. No. 6258467 and 387539.

[32] B. Saruhan, P. Francois, K. Fritscher, U. Schulz, Surface and Coatings Technology, 182 (2004) 175-183.

[33] B. Saruhan, U. Schulz, R. Vassen et al., Ceramic Engineering and Science Proceedings, (CESP), 25(4), 2004, 363-373.

[34] D. Wortman, 1999, Multilayer TBC, U.S. Pats. No. 5, 942, 334 and 5792521.

[35] T. Krell, U. Schulz, M. Peters, W.A. Kaysser, Graded EB-PVD alumina-zirconia thermal barrier coatings- an experimental approach, in: FGM 98, ed. W.A. Kaysser, Trans Tech Publications LTD, 396-401 (1999).


[36] M. Peters, C. Leyens, U. Schulz, W.A. Kaysser, Advanced Engineering Materials, 3 (2001) 193-204.

[37] M. Maloney, Method for producing ceramic coatings with layered porosity, U.S. Pat. No. 6365236, (2002).