Yttria-stabilized zirconia (YSZ)-mullite multilayer architectures with compositional grading between the bond coat and YSZ top coat are envisioned as solutions to ease their coefficient of thermal expansion mismatch induced stress. In this work, two different types of mullite powder (spray-dried and freeze-granulated) and a mullite-YSZ 75/25 vol.% mixture spray-dried powder were employed. Using instrumented indentation with loads between 10 and 500 mN, the role of the powder characteristics on the mechanical behavior of air plasma-sprayed mullite bond coats deposited on SiC substrates was investigated. Hardness (H) and elastic modulus (E) were measured for the as-sprayed coatings and for coatings heat-treated at 1300 °C, in water vapor environment, for periods up to 500 h. Both H and E values of the coatings are found to be highly dependent on the size distribution of the starting powders. It is aimed the fabrication of an efficient and cost-effective EBC prototype based on YSZ compositionally graded mullite.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
K.N. Lee, Current Status of Environmental Barrier Coatings for Si-Based Ceramics, Surf. Coat. Technol., 2000, 133-134, p 1-7
S. Latzel, R. Vaßen, and D. Stöver, New Environmental Barrier Coating System on Carbon-Fiber Reinforced Silicon Carbide Composites, J. Therm. Spray Technol., 2005, 14, p 268-272
K.N. Lee, D.S. Fox, and N.P. Bansal, Rare Earth Silicate Environmental Barrier Coatings for SiC/SiC Composites and Si3N4 Ceramics, J. Eur. Ceram. Soc., 2005, 25, p 1705-1715
H. Schneider, J. Schreuer, and B. Hildmann, Structure and Properties of Mullite: A Review, J. Eur. Ceram. Soc., 2008, 28, p 329-344
N.S. Jacobson, Corrosion of Silicon-Based Ceramics in Combustion Environments, J. Am. Ceram. Soc., 1993, 76, p 3-28
N.S. Jacobson, D.S. Fox, J.S. Smialek, E.J. Opila, C. Dellacorte, and K.N. Lee, Performance of Ceramics in Severe Environments, ASM Handbook, Vol. 13B Corrosion Materials, p 565
U. Schulz, M. Peters, Fr.-W. Bachb, and G. Tegeder, Graded Coatings for Thermal, Wear and Corrosion Barriers, Mater. Sci. Eng. A, 2003, 362, p 61-80
T.W. Murray, O. Balogun, T.L. Steen, S.N. Basu, and V.K. Sarin, Inspection of Compositionally Graded Mullite Coatings Using Laser Based Ultrasonics, Int. J. Refract. Met. Hard Mater., 2005, 23, p 322-329
C. Cano, E. Garcia, A.L. Fernandes, M.I. Osendi, and P. Miranzo, Mullite/ZrO2 Coatings Produced by Flame Spraying, J. Eur. Ceram. Soc., 2008, 28, p 2191-2197
P.K. Rohatgi, N. Gupta, and S. Alaraj, Thermal Expansion of Aluminum-Fly Ash Cenosphere Composites Synthesized by Pressure Infiltration Technique, J. Compos. Mater., 2006, 40(13), p 1163-1174
R. Asthana, A. Kumar, and N.B. Dahotre, Materials Processing and Manufacturing Science, Elsevier, Amsterdam, 2006
E. Garcia, J. Mesquita-Guimarães, P. Miranzo, and M.I. Osendi, Procedure for Obtaining Ceramic Feedstock for Thermal Spraying Applications, Patent 2009, ICV-CSIC, Ref. ES1641.581, Spain
W.C. Oliver and G.M. Pharr, Measurement of Hardness and Elastic Modulus by Instrumented Indentation: Advances in Understanding and Refinements to Methodology, J. Mater. Res., 2004, 19(1), p 3-20
R. McPherson, A Review of Microstructure and Properties of Plasma sprayed Ceramic Coatings, Surf. Coat. Technol., 1989, 39-40, p 173-181
E. Garcia, J. Mesquita-Guimarães, P. Miranzo, M.I. Osendi, C.V. Cojocaru, Y. Wang, C. Moreau, and R.S. Lima, Phase Composition and Microstructural Responses of Crystalline Mullite/YSZ Coating Under Water Vapor Environments, Thermal Spray: Global Solution for Future Application (ITSC 2010 Proceedings), DVS-Verlag GmbH, Dusseldorf, Germany, 2010, PDF Format (CD)
A.A. Elmustafaa and D.S. Stone, Nanoindentation and the Indentation Size Effect: Kinetics of Deformation and Strain Gradient Plasticity, J. Mech. Phys. Solids, 2003, 51, p 357-381
B.-K. Jang, Influence of Low Indentation Load on Young’s Modulus and Hardness of 4 mol% Y2O3-ZrO2 by Nanoindentation, J. Alloy Compd., 2006, 426, p 312-315
C.V. Cojocaru, S. Kruger, C. Moreau, and R.S. Lima, Mechanical Properties and Behaviour of BSAS/Mullite-Based Environmental Barrier Coatings Exposed to High Temperature in Water Vapour Environment, Thermal Spray: Global Solution for Future Application (ITSC 2010 Proceedings), DVS-Verlag GmbH, Dusseldorf, Germany, 2010, PDF Format (CD)
R.S. Lima and B.R. Marple, Toward Highly Sintering-Resistant Nanostructured ZrO2-7 wt.% Y2O3 Coatings for TBC Applications by Employing Differential Sintering, J. Therm. Spray Technol., 2008, 17, p 846-852
The NRC team of authors acknowledges valuable technical support from the technical officers of the Surface Technology Group for samples production, metallographic preparation, and SEM analysis. This work has been supported by NRC-CSIC program (project 2007CA003).
This article is an invited paper selected from presentations at the 2010 International Thermal Spray Conference and has been expanded from the original presentation. It is simultaneously published in Thermal Spray: Global Solutions for Future Applications, Proceedings of the 2010 International Thermal Spray Conference, Singapore, May 3-5, 2010, Basil R. Marple, Arvind Agarwal, Margaret M. Hyland, Yuk-Chiu Lau, Chang-Jiu Li, Rogerio S. Lima, and Ghislain Montavon, Ed., ASM International, Materials Park, OH, 2011.
About this article
Cite this article
Cojocaru, C.V., Wang, Y., Moreau, C. et al. Mechanical Behavior of Air Plasma-Sprayed YSZ Functionally Graded Mullite Coatings Investigated via Instrumented Indentation. J Therm Spray Tech 20, 100–107 (2011). https://doi.org/10.1007/s11666-010-9586-9
- elastic modulus
- environmental barrier coatings
- water vapor