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

摘要

A new process where a melt jet is quenched in gasfollowed by winding in a rotating liquid, which is a modifiedprocess of the in-rotating-water-spinning Process (INROLISP), hasbeen developed in order to make continuous Fe-6.5 mass% Si alloyfiber with primary dendrite arms parallel to the fiber axis, havingnearly zero magnetostriction. The molten alloy is ejected from anozzle through a He gas zone located just under the nozzle,followed by an 02 gas zone. He gas protects the orifice fromplugging with metal oxides. The oxygen in the next zone forms ametal oxide sheath on the jet surface to restrain the jet frombreaking up. The straight jet covered with oxide film continuouslysolidified and caused recalescence. After the recalescence the fiberwas wound in a rotating liquid. Without the oxidization zone, suchas only He or only NH3 vapor, the jet was more rapidly cooled butbecame fractured. In case of CO2 in the oxidization zone, the jetbecame fractured and led to short fibers. The capillary breakuplength of a jet (LBU) can be calculated by LBU =K V (p d3Iy)1/2,where V is mean velocity of a jet, p the density of the molten alloy,d the diameter of nozzle, and y the surface tension of the moltenalloy. In this work, the coefficient K was estimated as 10-20 fromthe experimental results for the He zone length and the velocity ofthe jet. The spinning gap between the nozzle exit and the rotatingliquid surface was set 0.2-1.0 m which is longer than the lengthbetween the nozzle exit and the start of recalescence. Fibers aboutless than 100 μm in diameter, longer than 10 m in length, havinga large Barkhausen effect were obtained.