Thermal Diffusivity of Ba-MICA and Ba-MICA/Yttria-Stabilized Zirconia Composites
In search of alternate sources for generating and storing energy, ionically conductive ceramics are being investigated. Stabilized zirconia is one such material. Its thermal shock resistance is, however, relatively low. By preparing ceramic composites of stabilized zirconia with a dispersed second phase — a synthetic Ba-mica in this case — the thermal shock resistance of the basic material can be enhanced.
Previous measurements in this laboratory of thermal transport properties of Ba-mica/yttria-stabilized zirconia composites, as well as the measurements by others on similar composites, have produced somewhat unexpected results. To expand on these measurements, a specimen of solid Ba-mica as well as an additional Ba-mica/yttríastabilized zirconia composite were prepared and their thermal diffusivities determined in the range of 25° to 700°C. Measurements on oxygen deficient Ba-mica/zirconia composite indicate that oxygen vacancy formation appreciably depresses the thermal transport properties.
KeywordsThermal Diffusivity Thermal Shock Resistance Graphite Mold Thermal Diffusivity Measurement Thermal Transport Property
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- 3.Wheat, T.A. “Development of Zirconia Electrolyte for use in a steelmaking oxygen. probe”; CANMET Report 76–13; CANMET, Energy, Mines and Resources Canada; 1975.Google Scholar
- 5.Hasselman, D.P.H. “Micromechanical thermal stresses and thermal stress resistance of porous brittle ceramics”; ibid; 52: 4: 215–6; 1969.Google Scholar
- 6.Hasselman, D.P.H. “Unified theory of thermal shock fracture initiation and crack propagation in brittle ceramics”; ibid; 52: 11; 600–6; 1969.Google Scholar
- 7.Hasselman, D.P.H. and Shaffer, P.T.B. “Factors affecting thermal shock resistance of polyphase ceramic bodies, Pt. II”; Techn Rept WADD-TR-60–749; Contract AF 33 (616)-6806, 155 pp.; April 1962.Google Scholar
- 9.Lange, F.F. “Fracture energy and strength behaviour of a sodium borosilicate glass–Al203 composite system”; ibid; 54: 12: 614–20; 1971.Google Scholar
- 10.McCauley, J.W. “Fabrication of novel composites - Part II: fabrication and properties of Ba-mica/Al203 composites”; AMMRC TR 73–32, Army Materials and Mechanics Research Center, Watertown, Massachusetts, U.S.A.; May 1973.Google Scholar
- 11.Youngblood, G.E., Gentsen, L.D., McCauley, J.W. and Hasselman, D.P.H. “Thermal Diffusivity of Ba-mica/alumina composites”; Am Cer Sec Bull; 58: 6: 620–1; 1979.Google Scholar
- 12.Tye, R.P. and McCauley, J.W. “The thermal conductivity and linear expansion of Ba-mica/alumina composite materials”; Rev Int Hautes Temp Refract; 12: 6: 100–5; 1975.Google Scholar
- 13.Markovich, V.V. “Thermal diffusivity of yttria-stabilizied zirconia”; High Temp–High Pressures; 8: 2: 231–5; 1976.Google Scholar
- 14.Mirkovich, V.V. “Thermal diffusivity of Ba-mica/yttria-stabilized zirconia composites”; to be published in Rev Int Hautes Temp Refract; 1979.Google Scholar
- 16.Phillipi, C.M. and Mazdiyasni, K.S. “Infrared and raman spectra of zirconia polymorphs”; ibid; 54: 5: 254–8; 1971Google Scholar
- 18.Mirkovich, V.V. “An apparatus for measuring thermal diffusivity in air”; CANMET Report 77–21; CANNET, Energy, Mines and Resources Canada; 1976.Google Scholar