Method of making a high current density cathode
US4444718A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 1982 |
| Grant date | Apr 24, 1984 |
| Priority date | — |
| Expiry date | Mar 19, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J9/047
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high current density cathode is made by first forming an active porous h purity tungsten pellet by the steps of: PA0 (A) mixing tungsten powder with about 1 to 5 percent by weight of the mixture of an activator powder and compacting the powders at a pressure of about 35 tons per square inch to form a pellet, PA0 (B) sintering the pellet in a non-oxidizing atmosphere at about 1800 degrees C. for about 11/2 to 31/2 hours to the desired porosity, PA0 (C) filling the porous pellet with a filler material, PA0 (D) machining to the desired size and shape, PA0 (E) removing the filler material, and then forming the cathode by impregnating the pellet with Ba.sub.5 Sr(WO.sub.6).sub.2 at about 1700 degrees C. in an inert atmosphere and subsequently firing for 2 minutes at 1800 degrees C. in dry hydrogen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.