1991 Fiscal Year Final Research Report Summary
Phase Transformation and Precipitation in Partially-Stabilized Zirconia
| Project/Area Number |
01470061
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
金属材料(含表面処理・腐食防食)
|
|---|
| Research Institution | The university of Tokyo |
|---|
Principal Investigator |
SAKUMA Taketo Professor, University of Tokyo, 工学部, 教授 (50005500)
|
|---|
| Project Period (FY) |
1989 – 1991
|
| Keywords | zirconia / phase transformation / phase transition / microstructure / precipitation / spinodal decomposition / 微構造 |
|---|
| Research Abstract |
The microstructure formed by the cubic-to-tetragonal (c-t) transformation was examined in detail. The domain structure and plate-like or lenticular microstructures were developed in tetragonal zirconia (t-ZrO_2) generated by rapid cooling from high-temperature cubic phase (cZrO_2). The c-t transformation was always completed with a formation of the domain structure. The modulated structure characteristic of spinodal decomposition was found in ZrO_2-Y_2O_3 annealed in the c-t two-phase region. From the microstructural evidence, the author has proposed that the c-t transformation has a nature of second-order phase transition.
The thermodynamic analysis on the c-t equilibrium was made by assuming that this transformation is of the second-order type. The result satisfactorily explained the reported c-t equilibrium.
|
