Method of manufacture of permanent magnets magnetically anisotropic in the form of bars, with a cubic crystalline structure and to the axial orientation of the crystals in the main direction 100

摘要

An elongated anisotropic permanent magnet having a cubic crystal structure with the [100] direction orientated longitudinally is produced from an Fe-Ti-Co-Ni-Al alloy by progressive crystallization using a seed of the same or similar composition. The rate of solidification is adjusted (depending on Ti content in accordance with Fig., not shown) to produce a (BH) max value of at least 9 x 106GOe. The alloy is composed of 1-10% of Ti, 16-42% of Co, 7-20% of Ni, 6-11% of Al, 1-10% of Cu, 0-4% of Nb, 0-8% of Ta, 0-1% of Si, 0-1% of S, and the balance Fe and impurities. An oxide film between seed and melt may be removed by natural convection currents (when the melt has a diameter of greater than 10 mm), mechanically or by the use of cryolite. A charge rod supported on a seed in an open ended aluminium tube may be lowered from a tungsten-hairpin oven.ALSO:An elongated anisotropic permanent magnet having a cubic crystal structure with the [100] direction orientated longitudinally is produced from an Fe-Ti-Co-Ni-Al alloy by progressive crystallization using a seed of the same or similar composition. The rate of solidification is adjusted (depending on Ti content in accordance with Fig., not shown) to produce a (BH) max value of at least 9 x 106 GOe. The alloy is composed of 1 - 10% of Ti, 16 - 42% of Co, 7 - 20% of Ni, 6 - 11% of Al, 0 - 10% of Cu, 0 - 4% of Nb, 0-8% of Ta, 0-1% of Si, 0-1% of S and balance Fe and impurities. An oxide film between seed and melt may be removed by natural convection currents (when the melt has a diameter of greater than 10 mm), mechanically or by the use of cryolite. A charge rod supported on a seed in an open ended aluminium tube may be lowered from a tungstenhairpin oven.