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

Abstract

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 Fe 40Ni 40P 14B 6 ribbons increase in the range 4×10 4–6.9×10 6 K s −1 while ribbon thickness decreases from 92 to 18 μm 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 ̇ ∝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.