December 2003 Communications of the American Ceramic Sociery 2227 one. However, an interesting feature is characterized here, in Fig F F Lange, G L. Dunlop, and B side of the grain boundary. Theoretically, it has been shown/7 4. A transfor med lath starts at one gra d goes through the oth Transformation Toughened / -,O, Materials at 250C./,Am. 21237-40019 al domains. This would explain very nicely the observed Zirconia at 370 K under a Low Applied Stress, Mater. Sci. Eng- A297. 26-30 "R Guo. D, Guo, D. Zhao. Z. Yang, and Y. Chen, "Low Temperature Ageing in IV. Conclusion Water Vapor and Mechanical Properties of ZTA Ceramics, Mater. Left, 86 III Observations of martensitic relief of a few dozens of nanome. ers in yttria-stabilized zirconia by atomic force microscopy in Its Role in transformation“PmM.4146357 contact mode are reported here for the first time. The different F. Lange. Transformation Toughening. Part 1: Size Effects Associated wi features showed here fit very well the model of martensitic the Thermodynamics of Constrained Transformations. "J. Mater. Sci. 17,255-62 transformation. The junction planes angle correspondence and the (1982) progressive invasion of martensite laths with different orientation J. Chevalier. B, Cales, and J M Drouin. "Low-Temperature Aging ef Y-TZP was observed. Transgranular monoclinic variants also appeared, as Ceramies,J. Am. Ceram. So, 82 1812150-54(1999) M. Hayakawa. K. Adachi,and predicted theoretically by some authors. Using AFM should bring bservations of martensitic features that were not accessible by M例x22m,A other techniques uroda. and M. Nihe,"Surface Relief Associated with Isothermal Martensite in Zirconia-3-moler-Yttria Ceramies Ohserved by Atomie References Force Microscopy, J, Am. Ceram Soc., 82 1ID12921-23(1999) L W: Chen and Y. H. Chiao, "Martensitic Nucleation in /ro). Acta Metall, 31 D. J. Green, R H J Hannink, and M V, Swain, Trnsformation Toughening of 01627-38(1983 cronies. CRC Press, Boca Raton FL 198 I Y. H Chiao and I. w. Chen, ""Martensitic Growth in Z,-An in Situ, Small A Gi. Evans and A H. Heuer. "Review-Transformation Toughening in Ceram- Particles, TEM Study of a Single Interlace Transformation." Acta Metall. Mater. 38 Martensite Transformation in Crack-Tip Stress Fields, J, Am, Ceram, Soc. 6.3 611163-7401990 6]241-48(1980 E P. Butler and A. H. Heuer, " X-ray Micmanalysis of Zro, Particles in ZrO,- Toughened AL-O,, "J, An. Cerim. So, 65 1121C-206-C-207(1982) "L Gtemillar. T. Epicier, J. Chevalier, and G, Fantozzi. "Microstructural Study 3|61485-502(1995) ot Silica-Doped Ceramics, Acta Mater, 48. 4647-52 200 H. Tsubakino, M. Hanamoto, and R Notato. "Tetragonal to Monocline Phase S. Schmatder and H. Schubert."Sign of Intemal Stresses for the Transformation dunng Thenmal Cycling and Iso Ageing in Yttria-Partially Martensitic Transformation in Yitria- Stabilized Tetragonal Zirconia polycrystals during Degradation. "J. An. Ceran. Sec., 69 [71 534(1986)