EFFECT OF SPINNING CONDITION ON NON-CRYSTALLINITY OF FE77.5SI7.5B15 (AT-PERCENT) WIRE PRODUCED BY IN-ROTATING-WATER SPINNING METHOD

The effect of spinning condition on the quality of Fe77.5Si7.5B15 (at% ) wires produced by the In-Rotating-Water Spinning Method was examined experimentally. The diameter of the injection nozzle was 0.25 mm. Lon g continuous wires with round cross section were obtained when the mol ten-jet velocity nu(j) was a little higher than the drum velocity nu(d ), whereas the wire became meanderous with the increase in nu(j)/nu(d) . The heat of crystallization Delta H, which expresses the degree of n on-crystallinity of the wire, remained almost constant for 0.77 < nu(j )/nu(d) < 1. For this case the wires were estimated to be almost amorp hous judged from the X-ray diffraction pattern and the scanning electr on micrograph. For 1 < nu(j)/nu(d) < 1.32, however, Delta H decreased with increasing nu(j)/nu(d). The temperature distribution of the jet w as measured by the photo-calorimetric method. For the water temperatur e of 10 degrees C, the average cooling rate of the jet between 1470 to 1200 K, was found to be 6 x 10(4) to 9 x 10(4) K/s. The measured cool ing rate did not show any correlation with Delta H. This indicated tha t the quality of the wire was determined by the cooling rate in the do wnstream region with a lower temperature.