Effects of Wheel Surface Conditions on the Casting of Amorphous Metal Ribbons

The wetting of the liquid metal on the casting wheel surface is important in the continuous casting of amorphous metal ribbons. The wetting characteristics are substantially revealed by the wetting pattern on the wheel-side surface of the ribbon, which consists of areas of air pockets and areas of direct contact between metal and wheel. Experimental results will be presented regarding the effects of the condition of the casting wheel surface on the wetting pattern and the related interfacial phenomena such as the ribbon surface smoothness, the heat transfer at metal-wheel interface, and the separation of ribbon from the wheel. In particular, the mechanism of formation of the periodic ribbon surface defect known as “fish scale” and the elimination of this defect by changing the condition of the casting wheel surface will be discussed.