| Numéro |
J. Phys. Colloques
Volume 49, Numéro C5, Octobre 1988
Interface Science and Engineering '87An International Conference on the Structure and Properties of Internal Interfaces |
|
|---|---|---|
| Page(s) | C5-611 - C5-616 | |
| DOI | https://doi.org/10.1051/jphyscol:1988577 | |
An International Conference on the Structure and Properties of Internal Interfaces
J. Phys. Colloques 49 (1988) C5-611-C5-616
DOI: 10.1051/jphyscol:1988577
EFFECT OF THERMAL AGING ON MECHANICAL AND ELECTRICAL PROPERTIES OF THE MgO-PARTIALLY STABILIZED ZIRCONIA BODIES
H.-J. JUNG1, Y.-J. OH1 et H.-L. LEE21 Inorganic Materials Laboratory, KAIST, PO Box 131, Cheongryang, Seoul, Korea
2 Dept. of Ceramics Engineering, Yonsei University, 134 Shinchondong, Seoul, Korea
Abstract
The effects of thermal aging on some properties and thermal-shock behavior of zirconia partially stabilized with 9 mol% MgO (9MZ) were studied. 9MZ specimens were aged over 1300-1400°C for 12 hours subsequently after sintering at 1650°C for 4 hours. Fracture strength (both before and after thermal-shock test), linear thermal expansion, monoclinic fraction and phase transition by XRD, density, galvanic potential and microstructure were measured. Quantitative chemical analysis around the grain-boundary of the specimen aged at 1350°C was also conducted by EDX. The aging of 9MZ specimen causes a thermal decomposition of cubic-ZrO2 into the formation of metastable tetragonal-ZrO2 and MgO. The former increases the residual strength after thermal-shock test and the latter improves the thermal-shock resistance due to thermal conduction through the continuous phase of magnesia. The rate of thermal decomposition of cubic phase and the formation of monoclinic phase in matrix were increased with the decrease of aging temperature from 1400 to 1200°C. Galvanic potential of the aged specimen exhibited a proper emf characteristic.