Journal of Thermal Spray Technology

, Volume 22, Issue 2–3, pp 145–151 | Cite as

Atmospheric Plasma Sprayed Forsterite (Mg2SiO4) Coatings: An Investigation of the Processing-Microstructure-Performance Relationship

  • C. V. Cojocaru
  • J.-M. Lamarre
  • J.-G. Legoux
  • B. R. Marple
Peer Reviewed


Evaluating and understanding the relationship between processing, microstructure and performance of a dielectric coating is essential for its practical usage and reliable application. In this study, the role of the powder feedstock on the properties of atmospheric plasma sprayed forsterite (Mg2SiO4) dielectric coatings was investigated by using different forsterite powder granulometries. The microstructural and porosity characteristics of the coatings associated with the spray conditions employed were assessed via scanning electron microscopy (SEM) and image analysis. The phase composition of the coatings was studied via x-ray diffraction and their crystallinity index determined. The electrical insulating characteristics were investigated using the dielectric breakdown test and impedance spectroscopy measurements. The electrical properties obtained were correlated with the microstructural characteristics and a performance comparison between forsterite and other dielectric coatings is presented.


coefficient of thermal expansion dielectric coatings dielectric strength forsterite plasma-spray 



The authors acknowledge valuable technical support from the Surface Technology Group members: J.-C. Tremblay for APS sample production, J. Sykes and D. DeLagrave for metallographic preparation, and M. Thibodeau for SEM imaging. The authors also acknowledge Tom Arbanas from Du-Co Ceramics, PA, USA for useful discussions on forsterite powder processing and for providing experimental batches of fine powders.


  1. 1.
    J.R. Davis, Ed., Handbook of Thermal Spray Technology, ASM International, Materials Park, OH, 2004Google Scholar
  2. 2.
    S. Sampath, Thermal Sprayed Ceramic Coatings: Fundamental Issues and Application Considerations, Int. J. Mater. Prod. Technol., 2009, 35, p 425-448CrossRefGoogle Scholar
  3. 3.
    L. Golonka and L. Pawlowski, Ceramic on Metal Substrates Produced by Plasma Spraying for Thick Film Technology, Electrocomp. Sci. Technol., 1983, 10(2-3), p 143-150CrossRefGoogle Scholar
  4. 4.
    L. Pawlowski, The Relationship Between Structure and Dielectric Properties in Plasma-Sprayed Alumina Coatings, Surf. Coat. Technol., 1988, 35, p 285-298CrossRefGoogle Scholar
  5. 5.
    P. Ctibor, J. Sedlacek, and K. Neufuss, Influence of Chemical Composition on Dielectric Properties of Al2O3 and ZrO2 Plasma Deposits, Ceram. Int., 2003, 29, p 527-532CrossRefGoogle Scholar
  6. 6.
    S. Beauvais, V. Guipont, M. Jeandin, D. Juve, D. Treheux, A. Robisson, and R. Saenger, Influence of Defect Orientation on Electrical Insulating Properties of Plasma-Sprayed Alumina Coatings, J. Electroceram., 2005, 15, p 65-74CrossRefGoogle Scholar
  7. 7.
    C. Barry Carter and M. Grant Norton, Ceramic Materials: Science and Engineering, Springer, New York, 2007Google Scholar
  8. 8.
    W.D. Kingery, H.K. Bowen, and D.R. Uhlmann, Introduction to Ceramics, John & Wiley Sons, New York, 1976Google Scholar
  9. 9.
    T. Tsunooka, M. Androu, Y. Higashida, H. Sugiura, and H. Ohsato, Effects of TiO2 on Sinterability and Dielectric Properties of High Q Forsterite Ceramics, J. Eur. Ceram. Soc., 2003, 23, p 2573-2578CrossRefGoogle Scholar
  10. 10.
    T. Sugiyama, T. Tsunooka, K. Kakimoto, and H. Ohsato, Microwave Dielectric Properties of Forsterite-Based Solid Solutions, J. Eur. Ceram. Soc., 2006, 26, p 2097-2100CrossRefGoogle Scholar
  11. 11.
    K.X. Song, X.M. Chen, and X.C. Fan, Effects of Mg/Si Ratio on Microwave Dielectric Characteristics of Forsterite Ceramics, J. Am. Ceram. Soc., 2007, 90, p 1808-1811CrossRefGoogle Scholar
  12. 12.
    H.G. Wang, Y.M. Zhu, and H. Herman, Structure of Plasma-Sprayed Oxides in the MgO-Al2O3-SiO2 System, J. Mater. Sci., 1989, 24, p 4414-4418CrossRefGoogle Scholar
  13. 13.
    H.G. Wang and H. Herman, Thermomechanical Properties of Plasma-Sprayed Oxides in the MgO-Al2O3-SiO2 System, Surf. Coat. Technol., 1990, 42, p 203-216CrossRefGoogle Scholar
  14. 14.
    P. Ctibor, J. Sedlacek, K. Neufuss, J. Dubsky, and P. Chraska, Dielectric Properties of Plasma-Sprayed Silicates, Ceramic. Int., 2005, 31, p 315-321CrossRefGoogle Scholar
  15. 15.
    H. Samadi and T.W. Coyle, Modelling the Build-Up of Internal Stresses in Multilayer Thick Thermal Barrier Coatings, J. Therm. Spray Technol., 2009, 18, p 996-1003CrossRefGoogle Scholar
  16. 16.
    H. Samadi, L. Pershin, and T.W. Coyle, Effect of In-Flight Particle Properties on Deposition of Air Plasma Sprayed Forsterite, Surf. Coat. Technol., 2010, 204, p 3300-3306CrossRefGoogle Scholar
  17. 17.
    ASTM D149-09 Standard Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at Commercial Power FrequenciesGoogle Scholar
  18. 18.
  19. 19.
    O. Fukusuma, R. Tagashira, K. Tachino, and H. Mukunoki, Spraying of MgO Films with a Well-Controlled Plasma Jet, Surf. Coat. Technol., 2003, 169-170, p 579-582CrossRefGoogle Scholar
  20. 20.
    F.J.M. Rietmeijer, J.A. Nuth, J.M. Karner, and S.L. Hallenback, Gas-to-Solid Condensation in a Mg-SiO-H2-O2 Vapor: Metastable Eutectics in the MgO-SiO2 Phase Diagram, J. Chem. Phys., 2002, 4, p 546-551Google Scholar

Copyright information

© ASM International 2012

Authors and Affiliations

  • C. V. Cojocaru
    • 1
  • J.-M. Lamarre
    • 1
  • J.-G. Legoux
    • 1
  • B. R. Marple
    • 1
  1. 1.National Research Council of Canada (NRC)BouchervilleCanada

Personalised recommendations