Journal of Thermal Spray Technology

, Volume 27, Issue 4, pp 581–590 | Cite as

Mechanical Properties of Layered La2Zr2O7 Thermal Barrier Coatings

  • Xingye Guo
  • Li Li
  • Hyeon-Myeong Park
  • James Knapp
  • Yeon-Gil Jung
  • Jing Zhang
Peer Reviewed


Lanthanum zirconate (La2Zr2O7) has been proposed as a promising thermal barrier coating (TBC) material due to its low thermal conductivity and high stability at high temperatures. In this work, both single and double-ceramic-layer (DCL) TBC systems of La2Zr2O7 and 8 wt.% yttria-stabilized zirconia (8YSZ) were prepared using air plasma spray (APS) technique. The thermomechanical properties and microstructure were investigated. Thermal gradient mechanical fatigue (TGMF) tests were applied to investigate the thermal cycling performance. The results showed that DCL La2Zr2O7 + 8YSZ TBC samples lasted fewer cycles compared with single-layered 8YSZ TBC samples in TGMF tests. This is because DCL La2Zr2O7 TBC samples had higher residual stress during the thermal cycling process, and their fracture toughness was lower than that of 8YSZ. Bond strength test results showed that 8YSZ TBC samples had higher bond strength compared with La2Zr2O7. The erosion rate of La2Zr2O7 TBC samples was higher than that of 8YSZ samples, due to the lower critical erodent velocity and fracture toughness of La2Zr2O7. DCL porous 8YSZ + La2Zr2O7 had a lower erosion rate than other SCL and DCL La2Zr2O7 coatings, suggesting that porous 8YSZ serves as a stress-relief buffer layer.


bond strength erosion lanthanum zirconate thermal barrier coating thermal cycling 



This work received financial support from the US Department of Energy (grant no. DE-FE0008868, program manager: Richard Dunst) and Indiana University-Purdue University Indianapolis Research Support Funds Grant (RSFG) and International Research Development Fund (IRDF). Y.-G.J. also acknowledges financial support from the Human Resources Program in Energy Technology of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry, and Energy, Republic of Korea (No. 20174030201460).


  1. 1.
    J.H. Perepezko, The Hotter the Engine, the Better, Science, 2009, 326, p 1068-1069CrossRefGoogle Scholar
  2. 2.
    R. Vassen, X. Cao, F. Tietz, D. Basu, and D. Stover, Zirconates as New Materials for Thermal Barrier Coatings, J. Am. Ceram. Soc., 2000, 83, p 2023-2028CrossRefGoogle Scholar
  3. 3.
    X.Q. Cao, R. Vassen, and D. Stoever, Ceramic materials for thermal barrier coatings, J. Eur. Ceram. Soc., 2004, 24, p 1-10CrossRefGoogle Scholar
  4. 4.
    K. Bobzin, N. Bagcivan, T. Brögelmann, and B. Yildirim, Influence of temperature on phase stability and thermal conductivity of single- and double-ceramic-layer EB–PVD TBC top coats consisting of 7YSZ, Gd2Zr2O7 and La2Zr2O7, Surf. Coat. Technol., 2013, 237, p 56-64CrossRefGoogle Scholar
  5. 5.
    F.H. Brown and P.O.L. Duwez, The Systems Zirconia-Lanthana and Zirconia-Neodymia, J. Am. Ceram. Soc., 1955, 38, p 95-101CrossRefGoogle Scholar
  6. 6.
    R. Vaßen, F. Traeger, and D. Stöver, New Thermal Barrier Coatings Based on Pyrochlore/YSZ Double-Layer Systems, Int. J. Appl. Ceram. Technol., 2004, 1, p 351-361CrossRefGoogle Scholar
  7. 7.
    J. Feng, B. Xiao, R. Zhou, W. Pan, and D.R. Clarke, Anisotropic Elastic and Thermal Properties of the Double Perovskite Slab-Rock Salt Layer Ln2SrAl2O7 (Ln = La, Nd, Sm, Eu, Gd or Dy) Natural Superlattice Structure, Acta Mater., 2012, 60, p 3380-3392CrossRefGoogle Scholar
  8. 8.
    C. Wang, Y. Wang, S. Fan, Y. You, L. Wang, C. Yang et al., Optimized Functionally Graded La2Zr2O7/8YSZ Thermal Barrier Coatings Fabricated by Suspension Plasma Spraying, J. Alloys Compd., 2015, 649, p 1182-1190CrossRefGoogle Scholar
  9. 9.
    T. Liu, X. Chen, G.-J. Yang, and C.-J. Li, Properties Evolution of Plasma-Sprayed La2Zr2O7 Coating Induced by Pore Structure Evolution During Thermal Exposure, Ceram. Int., 2016, 42, p 15485-15492CrossRefGoogle Scholar
  10. 10.
    S. Sivakumar, K. Praveen, G. Shanmugavelayutham, S. Yugeswaran, and J. Mostaghimi, Thermo-Physical Behavior of Atmospheric Plasma Sprayed High Porosity Lanthanum Zirconate Coatings, Surf. Coat. Technol., 2017, 326, p 173-182CrossRefGoogle Scholar
  11. 11.
    G. Lyu, B.G. Kim, S.-S. Lee, Y.-G. Jung, J. Zhang, B.-G. Choi et al., Fracture Behavior and Thermal Durability of Lanthanum Zirconate-Based Thermal Barrier Coatings with Buffer Layer in Thermally Graded Mechanical Fatigue Environments, Surf. Coat. Technol., 2017, 332, p 64-71CrossRefGoogle Scholar
  12. 12.
    E. Bakan and R. Vaßen, Ceramic Top Coats of Plasma-Sprayed Thermal Barrier Coatings: Materials, Processes, and Properties, J. Therm. Spray Technol., 2017, 26, p 992-1010CrossRefGoogle Scholar
  13. 13.
    J. Zhang, X. Guo, Y.-G. Jung, L. Li, and J. Knapp, Lanthanum Zirconate Based Thermal Barrier Coatings: A Review, Surf. Coat. Technol., 2016, 323, p 18-29CrossRefGoogle Scholar
  14. 14.
    L. Wang, Y. Wang, X.G. Sun, J.Q. He, Z.Y. Pan, and C.H. Wang, Finite Element Simulation Of Residual Stress of Double-Ceramic-Layer La2Zr2O7/8YSZ Thermal Barrier Coatings Using Birth and Death Element Technique, Comput. Mater. Sci., 2012, 53, p 117-127CrossRefGoogle Scholar
  15. 15.
    F. Cernuschi, C. Guardamagna, S. Capelli, L. Lorenzoni, D.E. Mack, and A. Moscatelli, Solid Particle Erosion of Standard and Advanced Thermal Barrier Coatings, Wear, 2016, 348–349, p 43-51CrossRefGoogle Scholar
  16. 16.
    B. Baufeld, M. Bartsch, and M. Heinzelmann, Advanced Thermal Gradient Mechanical Fatigue Testing of CMSX-4 with an Oxidation Protection Coating, Int. J. Fatigue, 2008, 30, p 219-225CrossRefGoogle Scholar
  17. 17.
    M. Bartsch, B. Baufeld, S. Dalkiliç, L. Chernova, and M. Heinzelmann, Fatigue Cracks in a Thermal Barrier Coating System on a Superalloy In Multiaxial Thermomechanical Testing, Int. J. Fatigue, 2008, 30, p 211-218CrossRefGoogle Scholar
  18. 18.
    J. Zhang, J. Yu, X. Cheng, and S. Hou, Thermal Expansion and Solubility Limits of Cerium-Doped Lanthanum Zirconates, J. Alloys Compd., 2012, 525, p 78-81CrossRefGoogle Scholar
  19. 19.
    A.G. Evans, D.R. Mumm, J.W. Hutchinson, G.H. Meier, and F.S. Pettit, Mechanisms Controlling the Durability of Thermal Barrier Coatings, Prog. Mater. Sci., 2001, 46, p 505-553CrossRefGoogle Scholar
  20. 20.
    K. Jiang, S. Liu, G. Ma, and L. Zhao, Microstructure and Mechanical Properties of La2Zr2O7–(Zr0.92Y0.08)O1.96 Composite Ceramics Prepared by Spark Plasma Sintering, Ceram. Int., 2014, 40, p 13979-13985CrossRefGoogle Scholar
  21. 21.
    E.H. Jordan, M. Gell, D.M. Pease, L. Shaw, D.R. Clarke, V. Gupta, B. Barber, and K. Vaidyanathan, Bond Strength and Stress Measurements in Thermal Barrier Coatings, ASME 1997 International Gas Turbine and Aeroengine Congress and Exhibition, Orlando, Florida, June 2–5, 1997, Paper No. 97-GT-363, p V004T12A010Google Scholar
  22. 22.
    G.K. Beshish, C.W. Florey, F.J. Worzala, and W.J. Lenling, Fracture Toughness of Thermal Spray Ceramic Coatings Determined by the Indentation Technique, J. Therm. Spray Technol., 1993, 2, p 35-38CrossRefGoogle Scholar
  23. 23.
    C.H. Hsueh, Thermal Stresses in Elastic Multilayer Systems, Thin Solid Films, 2002, 418, p 182-188CrossRefGoogle Scholar
  24. 24.
    X.C. Zhang, B.S. Xu, H.D. Wang, and Y.X. Wu, An Analytical Model for Predicting Thermal Residual Stresses in Multilayer Coating Systems, Thin Solid Films, 2005, 488, p 274-282CrossRefGoogle Scholar
  25. 25.
    P.H. Townsend, D.M. Barnett, and T.A. Brunner, Elastic Relationships in Layered Composite Media with Approximation for the Case of Thin Films on a Thick Substrate, J. Appl. Phys., 1987, 62, p 4438-4444CrossRefGoogle Scholar
  26. 26.
    Y.C. Tsui and T.W. Clyne, An Analytical Model for Predicting Residual Stresses in Progressively Deposited Coatings Part 1: Planar Geometry, Thin Solid Films, 1997, 306, p 23-33CrossRefGoogle Scholar
  27. 27.
    D.B. Marshall, B.R. Lawn, and A.G. Evans, Elastic/Plastic Indentation Damage in Ceramics: The Lateral Crack System, J. Am. Ceram. Soc., 1982, 65, p 561-566CrossRefGoogle Scholar
  28. 28.
    D. Park, M.-W. Cho, and H. Lee, Effects of the Impact Angle Variations on the Erosion Rate of Glass in Powder Blasting Process, Int. J. Adv. Manuf. Technol., 2004, 23, p 444-450CrossRefGoogle Scholar
  29. 29.
    A.P. Verma and G.K. Lal, A Theoretical Study of Erosion Phenomenon in Abrasive Jet Machining, J. Manuf. Sci. Eng., 1996, 118, p 564CrossRefGoogle Scholar
  30. 30.
    P.J. Slikkerveer, P.C.P. Bouten, F.H. in’t Veld, and H. Scholten, Erosion and Damage by Sharp Particles, Wear, 1998, 217, p 237-250CrossRefGoogle Scholar
  31. 31.
    R.G. Wellman and J.R. Nicholls, A Monte Carlo Model for Predicting the Erosion Rate of EB PVD TBCs, Wear, 2004, 256, p 889-899CrossRefGoogle Scholar

Copyright information

© ASM International 2018

Authors and Affiliations

  1. 1.Department of Mechanical EngineeringIndiana University-Purdue UniversityIndianapolisUSA
  2. 2.Praxair Surface Technologies Inc.IndianapolisUSA
  3. 3.School of Materials Science and EngineeringChangwon National UniversityChangwonRepublic of Korea
  4. 4.College of Materials Science and EngineeringBeijing University of TechnologyBeijingChina

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