Numerical analysis of rapid solidification in a single roller process

The rapid solidification in a single roller process has been used to produce an amorphous ribbon. The thermal and fluid flow in that process is accompanied by free surfaces and a phase change. Since the cooling process is carried out over a very short time period, it is difficult to measure transient temperature distribution or cooling rates directly from the experiment. The present paper proposes a numerical method which is capable of simultaneously solving the thermal and fluid flow in molten metal and surrounding air and transient heat conduction in a cooling roller. The method, based on the VOF (Volume of Fluid) method, is improved to enable simulation of a transient two-dimensional thermal and fluid flow with a liquid-solid phase change and free surface. We simulated the cooling process of aluminum alloy amorphous ribbon. The shape of the amorphous ribbon, flow, temperature field and cooling rate were numerically obtained using parameters of the roll velocity, the nozzle slot breadth and the gap between nozzle and roller.