Solid solution matrix cathode
US5266414A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 18, 1988 |
| Grant date | Nov 30, 1993 |
| Priority date | — |
| Expiry date | Mar 18, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12174
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An impregnated thermionic cathode includes a porous matrix of sintered tungsten-alloy particles containing less than six percent iridium and/or other platinum-group metal. The pores of the matrix are impregnated with a temporary process impregnant such as molten copper or an organic monomer, and upon solidification is machined to a desired shape. Thereafter the temporary process impregnant is removed, and the matrix pores again infiltrated with a barium oxide such as molten barium aluminate, or other alkaline earth. A thin, iridium-rich surface activating layer, preferably of about 50% iridium, is then applied to the emitting surface. The diffusion of surface activating iridium is substantially blocked; superior emission and lifetime is provided; and the cathode is relatively low cost and easy to fabricate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.