GB445614A - Improvements in magnetic dust cores - Google Patents

Abstract

The electric resistivity of magnetic dust cores of iron alloys containing 0,5-16 per cent of silicon and 0,5-12 per cent of silicon is increased by the addition of one or more of the following: 2-25 per cent of manganese, less than 25 per cent of tin, 2-20 per cent of vanadium, less than 15 per cent of cobalt, 2-10 per cent of chromium, less than 8 per cent each of nickel, tungsten, antimony, and tantalum, less than 5 per cent each of molybdenum, arsenic, copper, phosphorus, sulphur, and silver, 2-5 per cent of titanium, less than 3 per cent each of zinc, magnesium, beryllium, boron, cadmium, bismuth, lead, and zirconium, the total amount of such additions being less than 40 per cent. The alloy is powdered and either oxidized on the surface by heating to less than 800 DEG C. or is mixed with insulating material with or without the addition of powdered iron, permalloy, or other magnetic material and the mixture pressed in moulds and heated; or the powder may be pasted to or otherwise incorporated with paper or fabric and made into cores.