Tiegelloses Zonenschmelzen hochschmelzender Metalle mit Hilfe von punktfokussierten Elektronenstrahlen

Summary In conventional systems for floating-zone melting with electron bombardment the use of ring-cathode electron guns is widely spread. However, little is known about the applicability of point-focus electron-beams for floating-zone melting. To study this type of process a floating-zone melting device with a horizontal specimen position and a single point-focus electron-beam has been constructed. The experiment showed that in spite of sagging of the molten zone due to gravity, it is possible to melt rods of all refractory metals with rod diameters up to 5 mm with well controllable operating characteristics. This method easily allows the growth of exactly oriented crystals of W, Ta, Mo and Nb using a goniometric holder with a seed crystal on one side. Some characteristics of this type of zone melting and some preliminary results of an investigation of the single crystals grown in this way are discussed.

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Gekürzte deutsche Fassung eines Vortrages, gehalten an «Second Internat. Conf. on Electron and Ion Beam Science and Technology», New York, April 1966.