Development of Phases in In Situ-Reacted Mullite-Zirconia Composites
For years it has been known that intimate mixtures of alumina (A12O3) and zircon (ZrSiO4) powders react at high temperatures to form mullite solid solution (3 A12O ·2 SiO2 to 2 A12O3 · SiO2) and zirconia (ZrO2). Due to the excellent high temperature strength, chemical inertness, thermal shock resistance and low thermal conductivity this reaction has been used in the production of high temperature refractories1. Work in the alumina-silica system (see for example ref. 2) has shown that pure mullite, when completely reacted and free of amorphous phase, is capable of producing bodies of extraordinary high temperature strength, subject to the limitations that most ceramics have, ie, brittleness. Recent work 3–7 has shown, however, that incorporation of zirconia particles into ceramic bodies, either in the monoclinic or tetragonal phase modification, is capable of greatly increasing the toughness and strength.
KeywordsElectron Energy Loss Spectroscopy Tetragonal Zirconia Tetragonal Symmetry Zirconia Particle Monoclinic Zirconia
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- 1.E.A. Thomas, French Patent 1, 320, 994 (1963)Google Scholar
- 5.N. Claussen, Fracture Toughness of A12O3 with an Unstabilized ZrO2-Dispersed Phase, ibid 59: 49 (1976)Google Scholar
- 7.N. Claussen, J. Steeb and R.F. Pabst, Effect of Induced Micro-cracking on the Fracture Toughness of Ceramics, J. Am. Ceram. Soc. 56: 559 (1977)Google Scholar
- 8.N. Claussen and J. Jahn, Mechanical Properties of Sintered In-Situ-Reacted Mullite-Zirconia Composites, ibid 63: 229 (1980)Google Scholar
- 10.E. Di Rupo and M.R. Anseau, Solid State Reactions in the ZrO2-SiO2 — A12O3 System, ibid 15: 111 (1980)Google Scholar
- 12.R.C. Garvie and P.S. Nicholson, Phase Analysis in Zirconia Systems, ibid 55: 6 303 (1972)Google Scholar
- 13.C.E. Curtis and H.G. Sowman, Investigation of the Thermal Dissociation, Reassociation and Synthesis of Zircon, ibid 36: 190 (1953)Google Scholar
- 14.Powder Diffraction File, Card. Nr. 15-776, Joint Committee on Powder Diffraction Standards, Swarthmore, Pa.Google Scholar
- 15.I. Patzak and H.D. Werner, Untersuchungen zur Charakerisierung von Standards für die quantitative röntgenographische Phasenanalyse, Ber. Dt. Keram. Ges. 54: 345 (1977)Google Scholar
- 16.F.F. Lange, Stress-Induced Phase Transformations: Theory of Phase Retention and Fracture Toughness, Technical Report Nr. 6, Rockwell International Science Center, October 1979Google Scholar
- 18.N. Claussen and M. Riihle, Design of Zirconia Toughened Ceramics, submitted to Advances in Ceramics, Proc. First Intern. Conf. on Zirconia, June 16–18th, 1980, CWRU, Cleveland, OhioGoogle Scholar