The effect of the melt-spinning of processing parameters on the rate cooling

The effect of the melt-spinning processing variables such as wheel speed, gas ejection pressure and melt temperature on cooling rates measured by a thermoelectric technique has been investigated. It is found that cooling rates during melt spinning of Fe40Ni40P14B6 ribbons increase in the range 4 x 10(4)-6.9 x 10(6) K s(-1) while ribbon thickness decreases from 92 to 18 mum with increasing wheel speed from 9 to 30.5 m s(-1). The resultant strong dependence of the rate of cooling on ribbon thickness (in this case <(T) over dot> infinity d(-3.1) is obtained. Cooling rates and ribbon thickness are found to increase with increasing ejection pressure and to decrease as melt superheat grows. As a result of improving thermal contact at the wheel-ribbon interface with increasing gas ejection pressure, the cooling rates of melt-spun ribbons tend to increase with their thickness. (C) 2002 Elsevier Science B.V. All rights reserved.