Process of preparing monolithic seal for sapphire CMH lamp
US6126889A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1998 |
| Grant date | Oct 3, 2000 |
| Priority date | — |
| Expiry date | Feb 11, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J9/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
845 A method of producing a ceramic-metal-halide (CMH) discharge lamp having a monolithic seal between a sapphire (single crystal alumina) arc tube and a polycrystalline alumina end cap. The method includes the steps of providing an arc tube of fully dense sapphire and providing an end cap made of unsintered compressed polycrystalline alumina powder. The end cap is heated until it is presintered to remove organic binder material at a low temperature relative to the sintering temperature. The presintered end cap is placed on an end portion of the arc tube to form an interface therebetween. The assembled presintered end cap and arc tube are then heated to the sintering temperature wherein the end cap is fully sintered onto the arc tube and the sapphire tube grows into the end cap. A monolithic seal is formed at the previous interface between the end cap and the arc tube as the sapphire tube grows into the polycrystalline alumina end cap.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.