PHYSICOTECHNICAL EXPEDIENT OF PERFECTION OF COMPOSITION STRIPS FOR CATHODES OF POWERFUL VACUUM DEVICES

Manufacture of powders from an intermetallic - rather fragile alloy, is not the considerable problem. However, in a mass production during a milling of a bullion application in globe mills of steel balls and in vibrating mills - hard-alloy balls, can be the reason of presence in ground «pulverous» powder Pd + Pd5Ba contaminants as the ferromagnetic particles. Presence of these impurities will fatally affect a level of emissive properties of secondary-electronic cathodes at their work in vacuum devices.

In this connection there is a necessity of disposal from powders Pd + Pd5Ba these undesirable impurities. With this purpose it will be necessary to subject powders to clearing of the ferromagnetic impurities. This additional operation can be lead in a small-sized magnetic cobber of drum-type type. Only after such clearing powders Pd + Pd5Ba it will be possible to inlet in palladic a powder at the rate of 2 % Ва in mix material.

Laboratory samples in the given work gained from powder mix material. They have been pressed in pressure casting dies with the sizes on thickness of 1,2 mm and 1,8 mm. At a stage of rolling it is model up to required thickness (0,5 m) sintered samples rolled on rigs of cold rolling for 2 transitions «annealing - rolling», that has proved good plasticity of a composition strap with powders Pd + Pd5Ba in comparison with the sample strap received from an alloy at the arc smelting.

Usually at the cathode materials define, as a rule, emissive properties. However now it is known, that emissive properties of viewed materials are provided appreciably with makeup and allocation of the emissive-fissile phase. In this connection in the given work the received samples were exposed to the check of their key properties. Methods of raster-type electron microscopy and X-ray spectral microanalysis with use of a mode of color cathode luminescence were applied