Accession Number : ADD009310

Title :   Improved Method of Making a High Current Density Cathode.

Descriptive Note : Patent Application,

Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC

Personal Author(s) : Smith,Bernard ; Freeman,Gerard L

Report Date : 19 Mar 1982

Pagination or Media Count : 6

Abstract : A high current density cathode is made by first forming an active porous high purity tungsten pellet by the steps of: (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, (B) sintering the pellet in a non-oxidizing atmosphere at about 1800 degrees C for about 1 1/2 to 3 1/2 hours to the desired porosity, (C) filling the porous pellet with a filler material, (d) machining to the desired size and shape, (E) removing the filler material, and then forming the cathode by impregnating the pellet with Ba5Sr(WO6)2 at about 1700 degrees C in an inert atmosphere and subsequently firing for 2 minutes at 1800 degrees C in dry hydrogen. (Author)

Descriptors :   *Patent applications, *Cathodes(Electron tubes), *Pellets, *Porous materials, Machining, Impregnation, Sintering, Rare gases, High density, Fillers, Hydrogen, Powders, Mixtures, Tungsten, Porosity, Drying, Mixing, Weight, Atmospheres, Barium compounds, Materials, Strontium compounds, Compacting, Cathodes, Activation, Tungsten oxides

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE