Abstract
The suspension plasma spraying (SPS) process has been developed to permit the feeding of sub-micrometer-sized powder into the plasma plume. In contrast to electron beam-physical vapor deposition and plasma spray-physical vapor deposition, SPS enables the cost-efficient deposition of columnar-structured coatings. Due to their strain tolerance, these coatings play an important role in the field of thermal barrier coatings (TBCs). In addition to the cost-efficient process, attention was turned to the TBC material. Nowadays, yttria partially stabilized zirconia (YSZ) is used as standard TBC material. However, its long-term application at temperatures higher than 1200 °C is problematic. At these high temperatures, phase transitions and sintering effects lead to the degradation of the TBC system. To overcome those deficits of YSZ, Mg-Al-spinel was chosen as TBC material. Even though it has a lower melting point (~2135 °C) and a higher thermal conductivity (~2.5 W/m/K) than YSZ, Mg-Al-spinel provides phase stability at high temperatures in contrast to YSZ. The Mg-Al-spinel deposition by SPS resulted in columnar-structured coatings, which have been tested for their thermal cycling lifetime. Furthermore, the influence of substrate cooling during the spraying process on thermal cycling behavior, phase composition, and stoichiometry of the Mg-Al-spinel has been investigated.
Similar content being viewed by others
References
B. Hallstedt, Thermodynamic Assessment of the System MgO-Al2O3, J. Am. Ceram. Soc., 1992, 75(6), p 1497-1507
S. Ebert, R. Mücke, D. Mack, R. Vaßen, D. Stöver, T. Wobst, and S. Gebhard, Failure Mechanisms of Magnesia Alumina Spinel Abradable Coatings Under Thermal Cyclic Loading, J. Eur. Ceram. Soc., 2013, 33(15-16), p 3335-3343
A. Guignard, G. Mauer, R. Vaßen, and D. Stöver, Deposition and Characteristics of Submicrometer-Structured Thermal Barrier Coatings by Suspension Plasma Spraying, J. Therm. Spray Technol., 2012, 21(3-4), p 416-424
A. Killinger, R. Gadow, G. Mauer, A. Guignard, R. Vaßen, and D. Stöver, Review of New Developments in Suspension and Solution Precursor Thermal Spray Processes, J. Therm. Spray Technol., 2011, 20(4), p 677-695
K. VanEvery, M.J.M. Krane, R.W. Trice, H. Wang, W. Porter, M. Besser, D. Sordelet, J. Ilavsky, and J. Almer, Column Formation in Suspension Plasma-Sprayed Coatings and Resultant Thermal Properties, J. Therm. Spray Technol., 2011, 20(4), p 817-828
Z. Tang, H. Kim, I. Yaroslavski, G. Masindo, Z. Celler, and D. Ellsworth, Novel Thermal Barrier Coatings produced by Axial Suspension Plasma Spray, Thermal Spray 2011: Proceedings of the International Thermal Spray Conference, B.R. Marple, A.Agarwal, M.M. Hyland, Y.-C. Lau, C.-J. Li, R.S. Lima, and A. McDonald, Ed., September 27-29, 2011 (Hamburg, Germany), DVS Media, ASM International, 2011, p 571
C. Delbos, J. Fazilleau, V. Rat, J.F. Coudert, P. Fauchais, and B. Pateyron, Phenomena Involved in Suspension Plasma Spraying Part 2: Zirconia Particle Treatment and Coating Formation, Plasma Chem. Plasma Process., 2006, 26(4), p 393-414
A. Bacciochini, G. Montavon, J. Ilavsky, A. Denoirjean, and P. Fauchais, Porous Architecture of SPS Thick YSZ Coatings Structured at the Nanometer Scale (~50 nm), J. Therm. Spray Technol., 2010, 19(1-2), p 198-206
S. Rezanka, G. Mauer, and R. Vaßen, Improved Thermal Cycling Durability of Thermal Barrier Coatings Manufactured by PS-PVD, J. Therm. Spray Technol., 2014, 23(1-2), p 182-189
G. Mauer and R. Vaßen, Plasma Spray-PVD, Plasma Characteristics and Impact on Coating Properties, J. Phys., 2012, 406(1), p 012005
K. von Niessen and M. Gindrat, Plasma Spray-PVD: A New Thermal Spray Process to Deposit Out of the Vapor Phase, J. Therm. Spray Technol., 2011, 20(4), p 736-743
R. Vaßen, F. Träger, and D. Stöver, New Thermal Barrier Coatings Based on Pyrochlore/YSZ Double-Layer Systems, Int. J. Appl. Ceram. Technol., 2004, 1(4), p 351-361
X.Q. Cao, R. Vaßen, F. Tietz, and D. Stöver, New Double-Ceramic-Layer Thermal Barrier Coatings Based on Zirconia-Rare Earth Composite Oxides, J. Eur. Ceram. Soc., 2006, 26(3), p 247-251
D.J. Marshall and A.N. Mariano, Cathodoluminescence of Geological Materials, Unwin Hyman, Boston, MA, 1988
F. Träger, R. Vaßen, K.-H. Rauwald, and D. Stöver, Thermal Cycling Setup for Testing Thermal Barrier Coatings, Adv. Eng. Mater., 2003, 5(6), p 429-432
G. Gutiérrez, A. Taga, and B. Johansson, Theoretical Structure Determination of γ-Al2O3, Phys. Rev. B, 2001, 65(1), p 012101
S. Cava, S.M. Tebcherani, I.A. Souza, S.A. Pianaro, C.A. Paskocimas, E. Longo, and J.A. Varela, Structural Characterization of Phase Transition of Al2O3 Nanopowders Obtained by Polymeric Precursor Method, Mater. Chem. Phys., 2007, 103(2-3), p 394-399
I. Levin and D. Brandon, Metastable Alumina Polymorphs, Crystal Structures and Transition Sequences, J. Am. Ceram. Soc., 1998, 81(8), p 1995-2012
R.K. Pati, J.C. Ray, and P. Pramanik, A Novel Chemical Route for the Synthesis of Nanocrystalline α-Al2O3 Powder, Mater. Lett., 2000, 44(5), p 199-303
H. Hara, T. Sasamoto, and T. Sata, Mass-spectrometric Study of the Vaporization of Magnesium Oxide from Magnesium Aluminate Spinel, Bull. Chem. Soc. Jpn., 1981, 54(11), p 3327-3333
J. Shou-Yong, L. Li-Bin, H. Ning-Kang, Z. Jin, and L. Yong, Investigation on Lattice Constants of Mg-Al Spinels, J. Mater. Sci. Lett., 2000, 19(3), p 225-227
A.F. Hollemann, E. Wiberg, and N. Wiberg, Lehrbuch der Anorganischen Chemie, 102nd ed., Walter de Gruyter, Berlin, 2007 [in German]
A.L. Gentile and W.R. Forster, Calcium Hexaluminate and Its Stability Relations in the System CaO-Al2O3-SiO2, J. Am. Ceram. Soc., 1963, 46(2), p 74-76
Acknowledgments
The authors kindly thank Mr. Karl-Heinz Rauwald, Mr. Ralf Laufs, and Mr. Frank Vondahlen for their support in the manufacturing of the sprayed samples. They acknowledge gratefully Dr. Doris Sebold for her SEM- and EDS-investigations, Dr. Yoo Jung Sohn for x-ray analysis, Mrs. Andrea Hilgers for the measurement of the particle-sizes and the viscosity, Mrs. Michaela Andreas for the powder preparation, and Mrs. Hiltrud Moitroux for the photographs of the specimens. Furthermore, they thank Mrs. Nicole Adels for the thermal cycling tests.
Author information
Authors and Affiliations
Corresponding author
Additional information
This article is an invited paper selected from presentations at the 2014 International Thermal Spray Conference, held May 21-23, 2014, in Barcelona, Spain, and has been expanded from the original presentation.
Rights and permissions
About this article
Cite this article
Schlegel, N., Ebert, S., Mauer, G. et al. Columnar-Structured Mg-Al-Spinel Thermal Barrier Coatings (TBCs) by Suspension Plasma Spraying (SPS). J Therm Spray Tech 24, 144–151 (2015). https://doi.org/10.1007/s11666-014-0138-6
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11666-014-0138-6