PRODUCTION PROCESS OF GRAIN ORIENTATION-C ONTROLLED FE-6.5 MASS-PERCENT-SI ALLOY FIBER USING SPINNING IN GAS ATMOSPHERE FOLLOWED BY WINDINGIN 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-W ater-Spinning Process (INROWASP), has been developed in order to make a continuous Fe-6.5 mass%Si alloy fiber with primary dendrite arms par allel to the fiber axis, having nearly zero magnetostriction. The molt en alloy is ejected down from a nozzle through the He gas zone located just under the nozzle, followed by the O-2 gas zone. Herium gas prote cts orifice plugging with metal oxides. Oxygen in the next zone forms the metal oxide sheath on the jet surface to refrain the jet from brea king up. The straight jet covered with oxide film was continuously sol idified and caused recalescence. After the recalescence the fiber was wound in the rotating liquid. In the atmosphere without the oxidizatio n zone, such as only He or NH3 vapor, the jet was more rapidly cooled but produced only particles. In the case of CO2 in the oxidization zon e, the jet became particles and short fibers. The capillary breakup le ngth of a jet (L-BU) can be calculated by L-BU=K . V .(rho.d(3)/gamma) (1/2), where V; mean velocity of a jet, rho; density of molten alloy, d; diameter of nozzle, gamma; surface tension of molten alloy. In this work, the coefficient K was estimated to be 10 similar to 20 from the experimental results for the zone length of He and the velocity of th e jet. The spinning gap between the nozzle exit and the rotating liqui d surface was set at 0.2 similar to 1.0 m which was longer than the le ngth between the nozzle exit and the start of recalescence. Fibers abo ut less than 100 mu m in diameter, longer than 10 m in length, having the large Barkhausen effect in the magnetic properties were obtained.