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Evaluation of Commercially Available Transformation Toughened Zirconia

Published online by Cambridge University Press:  25 February 2011

Jeffrey J. Swab*
Affiliation:
Materials Technology Laboratory, SLCMT-MCC, Watertown, MA 02172
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Abstract

Transformation toughened zirconia (TTZ) is a material being considered for use in advanced heat engines. However, at elevated temperatures TTZ materials undergo a phase transformation fron tetragonal to the monoclinic with an associated volume increase of approximately 5%.This transformation results in a loss of strength and fracture toughness. Six commercially available Japanese TTZ materials and one experimental domestic grade were examined for the extent and effect of this phasetransformation after exposure to elevated temperatures (1000 to 1200°C) for times of 100 and 500 hours. Tests completed to date show that all the TTZ materials examined transform and lose strength, but to various degrees. Strength losses after heat treatment at 1000°C for 100 and 500 hours, ranged from a high of 60% to as little as 7%. Additional heattreatments of 500 hours at 1100 and 1200°C were carried out on TTZ's whichhad strength losses of 15% or less after exposure to 1000°C.

Although the major thrust of this program is to examine the effects of high temperatures on TTZ materials, a preliminary examination of the effects of low temperatures on the properties is also being done. A small number of specimens are undergoing treatments at 200°C and ∼.8 MPa water vapor pressure for 50 hours. Early indications are that strength greatly reduced after this treatment.

Type
Articles
Copyright
Copyright © Materials Research Society 1987

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References

REFERENCE

1. Larsen, D. C. and Adams, J. W., ”Long-Term Stability and Properties of Zirconia Ceramics for Heavy Duty Diesel Engine Components,” prepared for NASA-Lewis Research Center, for US Department of Energy under Contract DEN 3-305 NASA CR-174943, Sept1985.Google Scholar
2. Schioler, L. J., ”Advanced Transformation Toughened Oxides,” prepared for US Department of Energy under Interagency Agreement DE-AI05-840R21411, (unpublished).Google Scholar
3. Schioler, L. J., Quinn, G. D., and Katz, R. N., ”Time-Temperature Dependence of the Strength of Commercial Zirconia Ceramics,” AMMRC TR 84-16, prepared for U.S. Department of Energy under Interagency Agreement DE-AE-101-77 CS51017, (April 1984).Google Scholar
4. Hecht, N. L., McCullum, D.E., Grant, D. W., Wolf, J. D., Graves, G. A., and Goodrich, S., ”The Experimental Evaluation of Environmental Effects in Toughened Ceramics for Advanced Heat Engines,” Proceedings of the 23rd Automotive Technology Development Contractors' Coordination Meeting, p. 299, Society of Automotive Engineers, Warrendale, PA, March 1986.Google Scholar
5. Ferber, M. K., and Hine, T., ”Time-Dependent Mechanical Behavior of Partially Stabilized Zirconia for Diesel Engine Applications,” IBID, p. 285.Google Scholar
6. Masaki, T., ”Mechanical Properties of Y2O3-Stabilized Tetragonal Polycrstals after Ageing at High Temperatures,” J. Am. Ceram. Soc., 69 [7], p. 519, (1986).Google Scholar
7. Tsukma, K., ”Mechanical Properties and Thermal Stability of CeO2 Containing Tetragonal Zirconia Polycrystals,” Am. Ceram. Soc. bull., 65 [10], p. 1386, (1986).Google Scholar
8. Ruhle, M. and Heuer, A. H., ”Phase Transformation in ZrO2 -ContainingCeramics: II, The Martensitic Reaction in t-ZrO2,” p. 14, Advances inCeramics, Vol.12, Science and Technology of Zirconia, ed. N., Claussen, M., Ruhle, and A. H., Heuer. The American Ceramic Society, (1984).Google Scholar
9. Sato, T. and Shimada, M., ”Crystalline Phase Change in Yttria-Partially- Stabilized Zirconia by Low-Temperature Annealing,” Comm. Am. Ceram.Soc., p. c212, (1984).CrossRefGoogle Scholar
10. Sato, T. and Shimada, M., ”Transformation of Yttria-doped Tetragonal ZrO2 Polycrystals by Annealing in Water,” J. Am. Ceram. Soc., 68 [6] p. 356, (1985).CrossRefGoogle Scholar
11. Sato, T., Ohtaki, S. and Shimada, M., ”Transformation of Yttria Partially Stabilized Zirconia by Low Temperature Annealing in Air,” J. Mat. Sci., [20] p. 1466 (1985).Google Scholar
12. Lange, F., ”Transformation Toughening - Part 2,” J. Mat. Sci., [17] p. 225, (1982).CrossRefGoogle Scholar