High electric resistant zirconia and/or hafnia ceramics
Abstract
Abstract Zirconia and/or hafnia-containing ceramics having high electric resistivity and mechanical strength which consists essentially of 5-30 mol % of at least one component of Group A consisting of YO 1 .5, ScO 1 .5, SmO 1 .5, EuO 1 .5, GdO 1 .5, TbO 1 .5, DyO 1 .5, HoO 1 .5, ErO 1 .5, TmO 1 .5, YbO 1 .5, LuO 1 .5, CaO and MgO, 5-40 mol % of at least one component of Group B consisting of NbO 2 .5 and TaO 2 .5 and 30-90 mol % of at least one component of Group C consisting of ZrO 2 and HfO 2 , said ceramics preferably satisfying the following equation Σ{(4-(ion valence number of each component of Group A))×(number of mole of each component of Group A)}≦(total number of mole of components of Group B). and crystal phase of said ceramics being preferred to be composed mainly of tetragonal phase.
Inventors
- 👤 Syunzo Mase
- 👤 Shigeo Soejima
Bibliographic Details
Claims Analysis
Total Claims: 4References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1988-03-25 | 1988-09-24 | 1989-03-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-25 | 1992-09-24 | 1993-03-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-25 | 1996-09-24 | 1997-03-26 | $7700.00 | Window Closed / Lapsed |