Three-dimensional transient temperature analysis of cooling roller for preparing amorphous ribbon

Planar flow casting (PFC) is a major method for industrial preparing amorphous ribbon. The key factors that affect ribbon formation in PFC are temperature and thermal stable time of cooling roller. This study proposes a new approach to investigate the transient three-dimensional temperature of the cooling roller using variable heat flux as the boundary condition. Firstly, the heat flux acted on the roller outer wall is calculated by two-dimensional heat transfer model. Employing the heat flux as the boundary condition, the three-dimensional transient temperature of the cooling roller is then analyzed. This study also examines the effects of the roller thickness and diameter on the temperature and stable time. Results show that the heat conduction in the roller not only in the radial direction but also in the width direction. The temperature is unevenly distributed, reaching the peak value in the middle width position, and the roller achieves thermal equilibrium after about 120 s of casting. In addition, the roller thickness mainly affects the stable time and the temperature of the inner wall; the diameter affects the stable time as well as the temperatures of both the inner and outer walls. Finally, the reliability of the simulation approach and results are verified by measuring the roller transient evolution temperature on the spot with the infrared thermal imager. This study provides the reference for the selection of roller parameters and the prediction of roller stable time during the PFC process.