Factors Controlling Thickness of Amorphous Ribbon in Single Roller Process

Ribbon formation in the single roller process was investigated to establish the casting process for ultra-wide ribbon. Observations of castings by photographs indicated that a melt puddle was formed between the nozzle and the wheel surface, and a ribbon was produced on the wheel surface. The thickness of the ribbon obtained was about 50 μm and this value was much smaller than the height of the melt puddle. Furthermore, the effect of the height and the length in the casting direction of the melt puddle on ribbon thickness was examined. The ribbon thickness was dependent on the length of the melt puddle in the casting direction, i.e., as the length of the melt puddle increased, the ribbon thickness increased. On the other hand, the ribbon thickness was independent of the height of the melt puddle. From the results of the present examinations, it is important to make the length of the melt puddle in the casting direction uniform across the width of the ribbon in order to obtain ultra-wide ribbon with uniform thickness.