Method of producing discharge lamp arc tubes
US4412963A · kind A · utility
Inventor
Key dates
| Filing date | Dec 18, 1981 |
| Grant date | Nov 1, 1983 |
| Priority date | — |
| Expiry date | Dec 18, 2001 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC04B2237/765
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention provides a method of producing discharge lamp arc tubes of ceramic material complete with metal cermet end closure members using initially incompletely fired sintered components and a sealing composition selected from silica, alumina and magnesia in proportions such that the composition falls within the accompanying ternary phase diagram BCDEFXYZPQ. The sealing compositions may also contain up to 5% by weight of nucleating agents such as phosphorous pentoxide, rare earth oxides, titania, zirconia or chromia. The inclusion of up to 5% by weight of boric oxide improves the flow characteristics and up to 10% by weight of Y.sub.2 O.sub.3, Yb.sub.2 O.sub.3, La.sub.2 O.sub.3, Dy.sub.2 O.sub.3, Eu.sub.2 O.sub.3, HfO.sub.2 improves the thermal and mechanical properties of the seals. The invention eliminates the need to make a first end seal by separate sintering and sealing operations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.