Abstract: A ceramic substrate is rapidly coated with a uniform coating of copper by ating the ceramic substrate to about 250.degree. C., adding an aqueous slurry of an inorganic copper salt to the ceramic substrate at that temperature, and heating the coated ceramic in a reducing atmosphere at about 800.degree. C.

Abstract: Metallic coatings are vacuum deposited onto a substrate using more than one eposition method in a single vacuum deposition chamber without breaking vacuum between depositions by providing a vacuum deposition chamber with an RF sputter electrode, a chemical vapor deposition assembly spaced from the sputter electrode, and a substrate that can be rotated from beneath the RF sputter electrode to beneath the chemical vapor deposition assembly, then cleaning and degassing the substrate under vacuum in the deposition chamber, then positioning the substrate below the RF sputter electrode, backfilling the chamber with argon, and then sputter depositing a metal coating onto the substrate and then rotating the coated substrate to beneath the chemical vapor deposition assembly, vacuum pumping the chamber, delivering the material to be chemically vapor deposited to the substrate surface, and heating the substrate to the temperature required for the chemical vapor deposition reaction to take place.

Abstract: A high current density long life cathode for use in high power microwave e applications is made by: machining a porous tungsten pellet with copper in its pores to the desired cathode shape to form the emitting surface of the cathode and cleaning the porous pellet ultrasonically in trichloroethylene, then acetone, and then methanol; firing the tungsten pellet at about 1800.degree. C in a reducing atmosphere; etching the tungsten pellet ultrasonically in a solution of 50 parts of concentrated nitric acid in 50 parts of water; ultrasonically cleaning the tungsten pellet for about five minutes in an aqueous alkaline solution; cleaning the tungsten pellet in hot deionized water and then air drying the tungsten pellet in an oven for five minutes at about 150.degree. C; refiring the tungsten pellet in a reducing atmosphere at about 1800.degree. C; impregnating the porous tungsten pellet with a mixture of Ba.sub.3 WO.sub.6, Ba.sub.2 SrWO.sub.6 and ZrH.sub.2 in a nonreducing, nonoxidizing atmosphere at about 1900.