Abstract
Aluminum oxide is widely used for plasma spraying. Alumina deposits consist of a number of metastable crystallographic modifications, which at elevated temperatures, transform to the stable α phase. It was shown that additions of various oxides changed the phase composition and shift phase transformation temperatures. This paper addresses the variation of phase compositions and temperatures of the phase changes for plasma-sprayed alumina deposits manufactured with alumina-base materials containing O2O3 and TiO2.
This study combines the results obtained from energy dispersive analyzer of X-rays (EDAX) and scanning electron microscopy (SEM) chemical analysis, differential thermal analysis (DTA), and X-ray powder diffrac-tion (XRD) quantitative phase analysis of as-sprayed and annealed samples of alumina deposits and shows how the two additives change the phase composition and the α-phase formation temperature. This transformation temperature varied by nearly 200 °C. The metastable alumina sequences were also influenced by the chemical composition; for example, the content of 6 alumina varied between 0 and 55 wt %.
Similar content being viewed by others
References
N.N. Ault, Characteristics of Refractory Oxide Coatings Produced by Flame-Spraying, J. Am. Ceram. Soc., Vol 40,1957, p 69–74
E. Dörre and H. Hübner, Alumina Processing, Properties, and Appli- cations, Springer-Verlag, Berlin, 1984, p 20–40
Powder Diffraction File, Alphabetical index, JCPDS, International Center for Diffraction Data, PA, USA, 1986
H. Herman, Plasma-Sprayed Coatings, Sci. Am., Vol 259 (No. 3), 1988, p 112–117
P. Raus and P. Chráska, Transmission Electron Microscope Study of a Plasma-Sprayed Zircon Coating, Ceramics (Silicaty), Vol 33 (No. 4), 1989, p 325–332 (in Czechoslovakian)
P. Chráska, J. Dubsky, B. Kolman, J. Ilavsky, and J. Forman, Study of Phase Changes in Plasma-Sprayed Deposits, J. Therm. Spray Tech- nol., Vol 1 (No. 4), 1992, p 301–306
I.A. Fisher, Variables Influencing the Characteristics of Plasma- Sprayed Coatings, Int. Met. Rev., Vol 17, 1972, p 117–129
C.X. Ding, R.A. Zatorski, and H. Herman, Oxide Powders for Plasma Spraying—The Relationship Between Powder Charac- teristics and Coating Properties, Thin Solid Films, Vol 118, 1984, p 467–475
J. Dubsky, B. Kolman, and P. Chráska, Influence of Cooling Rate on Phase Transformation in Alumina, Proc. of 7th Metallographic Sym- posium, Part 1, Czech Society for Sciences and Technology, High Ta- tras, Czechoslovakia, Kosice, 1989, p 168–171
G.N. Heintze and S. Uematsu, Preparation and Structures of Plasma- Sprayed β- and α-Al2O3 Coatings, Surf. Coat. Technol., Vol 50, 1992, p 213–222
M. Kumagain and G.L. Messing, Enhanced Densification of Boehmite Sol-Gel by α-Alumina Seeding, J. Am. Ceram. Soc., Vol 67, 1984, p C230-C231
G.L. Messing, M. Kumagai, R.A. Shellman, and J.L. McArdle, Seeded Transformation for Microstructural Control of Ceramic, The Science of Ceramic Chemical Processing, L.L. Hench and D.R. Ultrich, Ed., Wiley, 1986, p 259–271
G.C. Bye and G.T. Sympkin, Influence of Cr and Fe on Formation of α- Al2O3 from β-Al2O4, J. Am. Ceram. Soc., Vol 57, 1974, p 367–371
T. Tushida, R. Furiuchi, T. Ishii, and K. Itoh, The Effect of Cr3+ and Fe3+ Ions on the Transformation of Different Aluminum Hydroxides to (αAl2O3, Thermochim. Acta, Vol 64, 1983, p 337–353
I.A. Bonder, V.B. Glushkova, and P.A. Ceitlin, Study of Phase Transi- tions in Alumina, Inorganic Mater. (Neorganiceskie Materialy), Vol 7, 1971, p l367–1371
L. Giachetti and N. Tozzi, Quantitative Powder X-Ray Diffrac- tion of Some Ceramic Materials, Mater. Sci. Monography, Vol 16, 1983, p 185–195
R. Fillit, P. Homerin, J. Shafer, H. Bruyas, and F. Thevenot, Quantita- tive XRD Analysis of Zirconia-Toughened Alumina Ceramics, J. Ma- ter. Sci., Vol 22, 1987, p 3566–3570
H.K. Schmidt, Quantitative Analysis of Polymorphic Mixes of Zir- conia by X-Ray Diffraction, J. Am. Ceram. Soc., Vol 70 (No. 5), 1987, p 367–376
J. Wang, C.B. Poton, and P.M. Marquis, A Quantitative X-Ray Diffrac- tion Phase Analysis in the Reaction-Sintered Mullite Ceramic, J. Ma- ter. Sci. Lett., Vol 11, 1992, p 1301–1304
J. Ilavsky, Studies of Plasma-Sprayed Alumina, dissertation, State Uni- versity of New York, UMI, No. 9500218, 1994
N. Iwamoto, Y. Makino, and Y. Arata, “Crystallographical Considera- tions of Sprayed Alumina,” Paper 66, presented at 9th International Thermal Spraying Conference, (Hague, Netherlands), 1980
C. Misra, Activated Aluminas, Industrial Alumina Chemicals, ACS Monograph 184, American Chemical Society, 1986, p 73–106
Author information
Authors and Affiliations
Additional information
Part I of this article was printed in the September issue of JTST Vol 6 (No. 3), September 1997, p 320–326
Rights and permissions
About this article
Cite this article
Ilavsky, J., Berndt, C.C., Herman, H. et al. Alumina-base plasma-sprayed materials—Part II: Phase transformations in aluminas. J Therm Spray Tech 6, 439–444 (1997). https://doi.org/10.1007/s11666-997-0028-2
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/s11666-997-0028-2