Production process of grain orientation-controlled Fe-6.5 mass% Si alloy fiber using spinning in gas atmosphere followed by winding in rotating liquid

A new process where a melt jet is quenched in gas followed by winding in a rotating liquid, which is a modified process of the in-rotating-water-spinn ing Process (INROLISP), has been developed in order to make continuous Fe-6 .5 mass% Si alloy fiber with primary dendrite arms parallel to the fiber ax is, having nearly zero magnetostriction. The molten alloy is ejected from a nozzle through a He gas zone located just under the nozzle, followed by an O-2 gas zone. He gas protects the orifice from plugging with metal oxides. The oxygen in the next zone forms a metal oxide sheath on the jet surface to restrain the jet from breaking up. The straight jet covered with oxide f ilm continuously solidified and caused recalescence. After the recalescence the fiber was wound in a rotating liquid. Without the oxidization zone, su ch as only He or only NH3 vapor, the jet was more rapidly cooled but became fractured. In case of CO2 in the oxidization zone, the jet became fracture d and led to short fibers. The capillary breakup length of a jet (L-BU) can be calculated by L-BU = K . V . (rho . d(3)/gamma)(1/2), where V is mean v elocity of a jet, rho the density of the molten alloy, d the diameter of no zzle, and gamma the surface tension of the molten alloy. In this work, the coefficient K was estimated as 10-20 from the experimental results for the He zone length and the velocity of the jet. The spinning gap between the no zzle exit and the rotating liquid surface was set 0.2-1.0 m which is longer than the length between the nozzle exit and the start of recalescence. Fib ers about less than 100 mu m in diameter, longer than 10 m in length, havin g a large Barkhausen effect were obtained. (C) 1999 Elsevier Science S.A. A ll rights reserved.