Translucent polycrystalline alumina and method of making same
US5682082A · kind A · utility
44Cited by
10References
2Claims
0Family size
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Key dates
| Filing date | Jul 29, 1996 |
| Grant date | Oct 28, 1997 |
| Priority date | — |
| Expiry date | Jul 29, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J61/302
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An optically transparent polycrystalline alumina sintered body consists essentially of alumina, magnesia, yttria and zirconia. The magnesia is present in an amount of about 0.020 wgt. percent, the yttria is present in an amount of about 0.035 wgt. percent, and the zirconia is present in an amount of about 0.018 wgt. percent. An arc tube for a high pressure sodium lamp made from this composition has greatly increased resistance to sodium loss and concomitant outer jacket darkening, whereby the effective amount of lumen output is increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.