INFLUENCE OF THERMAL BUOYANCY ON FIBROUS EUTECTIC GROWTH .1. SEGREGATION RESULTS IN THE SN-CU6SN5 SYSTEM

The influence of thermal convection on mass transport in tin copper hy po-eutectic alloys is studied in a Bridgman type configuration. It is seen that a significant segregation can occur during solidification. T he axial composition profiles are fitted by means of a classical 1D bo undary layer model. In terms of radial segregation, the 2D computer si mulations performed for modelling account fairly well for the observed experimental results. An order of magnitude analysis is used to deriv e an asymptotic law for the maximal radial segregation in the solid, w hich is in good agreement with the numerical data.