Directional solidification using a baffle in microgravity

Numerical simulations were performed to optimize the conditions and paramet ers for directional solidification of Te-doped GaSb in reduced gravity rang ing from 10(-3) to 10(-5) g(0). Our key goal was to quantify the velocity a nd concentration fields with and without a baffle present in the melt. The effect of the distance of the baffle from the solid-liquid interface was in vestigated. When the baffle is placed 0.5 cm from the solid-liquid interfac e, acceleration of 10(-3) g(0) does not cause significant interference with segregation. Furthermore, the flow between the baffle and the interface (l ow Reynolds number "creeping" flow) does not depend on fluid properties (vi scosity). (C) 2001 Elsevier Science Ltd. All rights reserved.