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Journal of Thermal Spray Technology

, Volume 14, Issue 2, pp 231–238 | Cite as

Young’s modulus and fatigue behavior of plasma-sprayed alumina coatings

  • O. Kovářík
  • J. Siegl
  • J. Nohava
  • P. Chráska
Article

Abstract

The fatigue behavior and Young’s modulus of plasma-sprayed gray alumina on low-carbon steel substrates were investigated. The investigation of the properties of composites that were defined as “coating-substrate” composites included measurements of the microhardness profile, the residual stress on the top of the coating, and the residual stress profile in the substrate. Fatigue samples were periodically loaded as a cantilever beam on a special testing machine. Failed samples were observed with a scanning electron microscope to determine the failure processes in the coating. The Young’s modulus of the coating was measured by the four-point bending method. Samples were tested both in tension and compression under low (300 N) and high (800 N) loads. The authors’ experiments revealed that the average fatigue lives of coated specimens were nearly two times longer than those of the uncoated specimens. The measurements of Young’s modulus of the coating yielded values that varied between 27 and 53 GPa, with an average value of 43 GPa. Loading in tension caused a decrease in the Young’s modulus of the coating, while loading in compression led to an increase in Young’s modulus. The increase in the lifetime of coated samples was likely due to compressive residual stresses in the substrate, originating during the spray process. The failure of the coating was due to several processes, among which the most important were splat cracking, splat debonding, and the coalescence of cracks through the voids in the coating.

Keywords

alumina fatigue plasma spray Young’s modulus 

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References

  1. 1.
    F. Kroupa and J. Dubský, Pressure Dependence of Young’s Modulus of Thermal Sprayed Materials, Scr. Mater., Vol 40 (No. 11), 1999, p 1249–1254CrossRefGoogle Scholar
  2. 2.
    F. Kroupa and J. Plesek, Nonlinear Elastic Behavior in Compression of Thermally Sprayed Materials, Mater. Sci. Eng., A, Vol 328 (No. 1–2), 2002, p 1–7Google Scholar
  3. 3.
    J. Siegl, P. Kantor, and J. Adamek, Fatigue Processes in Bodies with Surface Coatings, Proceedings of the 14th International Conference on Surface Modification Technologies, T.S. Sudarshan and M. Jeandin, Ed., ASM International and IOM Communication Ltd., 2001, p 64–70Google Scholar
  4. 4.
    J. Siegl, P. Kantor, and J. Adamek, Investigation of Fatigue Processes in Bodies with Surface Coatings, Acta Technica, Vol 46, 2001, p 251–264Google Scholar
  5. 5.
    V. Harok and K. Neufuss, Elastic and Inelastic Effects in Compression in Plasma-Sprayed Ceramic Coatings, J. Thermal Spray Technol., Vol 10 (No. 1), 2001, p 126–132CrossRefGoogle Scholar
  6. 6.
    R.T.R. McGrann, D.J. Greving, J.R. Shadley, E.F. Rybicky, T.L. Kruecke, and B.E. Bodger, The Effect of Coating Residual Stress on the Fatigue Life of Thermal Spray Coated Steel and Aluminum, Surf. Coat. Technol., Vol 108–109, 1998, p 59–64CrossRefGoogle Scholar
  7. 7.
    L. Hernández, F. Oliveira, J.A. Berríros, C. Villalobos, A. Pertuz, and E.S. Puchi Cabrera, Fatigue Properties of a 4340 Steel Coated with Colmonoy 88 Deposit Applied by High-Velocity Oxygen Fuel, Surf. Coat. Technol., Vol 133–134, 2000, p 68–77CrossRefGoogle Scholar
  8. 8.
    O. Kesler, J. Matejicek, S. Sampath, S. Suresh, T. Gnaeupel-Herold, P.C. Brand, and H.J. Prask, Measurement of Residual Stress in Plasma-Sprayed Metallic, Ceramic and Composite Coatings, Mater. Sci. Eng., A, Vol 257 (No. 2), 1998, p 215–224CrossRefGoogle Scholar
  9. 9.
    L. Pawlowski, The Science and Engineering of Thermal Sprayed Coatings, J. Wiley, 1995Google Scholar
  10. 10.
    A. Kucuk, C.C. Berndt, U. Senturk, R.S. Lima, and C.R.C. Lima, Influence of Plasma Spray Parameters on Mechanical Properties of Yttria Stabilized Zirconia Coatings: I. Four Point Bend Test, Mater. Sci. Eng., A, Vol 284 (No. 1–2), 2000, p 29–40Google Scholar

Copyright information

© ASM International 2005

Authors and Affiliations

  • O. Kovářík
    • 1
  • J. Siegl
    • 1
  • J. Nohava
    • 2
  • P. Chráska
    • 2
  1. 1.Department of Materials, Faculty of Nuclear Sciences and Physical EngineeringCzech Technical UniversityPragueCzech Republic
  2. 2.Institute of Plasma PhysicsAcademy of Sciences of the Czech RepublicPragueCzech Republic

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