GB545926A - Improvements in or relating to electric discharge tubes - Google Patents

Abstract

545,926. Tungsten or molybdenum alloys. PHILIPS LAMPS, Ltd. (Naamlooze Vennootschap Philips'. Gloeilampenfabrieken). Sept. 9, 1941, No. 11557. [Class 82 (i)] [Also in Group XL] For use in an electric discharge tube, an independently heated cathode, which may be made by rolling one or more thin plates until a tubular body is obtained, and may be directly supported in an aperture of a mica or like plate, comprises an outer layer of nickel, copper, or the like on an inner layer consisting of an alloy of tungsten or molybdenum with one or two of the metals nickel, cobalt, and iron, with or without one or more of the elements aluminium, silicon, manganese, magnesium, zirconium, and thorium, the proportion of tungsten or molybdenum being respectively 10-25 and 10-35 atoms per cent. in alloys consisting of two components only and respectively 5-25 and 5-35 atoms per cent. in alloys consisting of more than two components. Specific examples consist of, by weight, (a)' 63 per cent. of nickel and 37 per cent. of tungsten; (b) 75.5 per cent. of nickel 20.5 per cent. of molybdenum, and 4 per cent. of aluminium; (c) 65 per cent. of nickel, 21 per cent. of molybdenum and 14 per cent. of iron; (d) 59.5 per cent. of nickel, 38 per cent. of tungsten and 2.5 per cent. of aluminium.