Modelling of rapid solidification by melt spinning: effect of heat transfer in the cooling substrate

An improved control volume integral method has been developed for the numerical modelling of heat transfer during the melt-spinning process. The heat transfers both inside the melt and in the substrate are incorporated directly in the numerical models. Several parametric studies have been conducted to investigate the effect of the heat transfer in the wheel, of the melt material and of the superheat level on the solidification characteristics, and in particular on the interface velocity and on the cooling rate at the interface. The calculations show also that the local substrate surface temperature may increase under the solidification puddle by several hundred kelvins, even for a copper wheel, and this surface temperature increase is found to have a significant impact on the solidification process. We believe that it is essential to include the surface heating factor in numerical models of melt spinning and other rapid solidification processes relying on direct contact with a solid substrate.