Influence of microgravity on the back-diffusion phenomenon in the Al-3.5 Li alloy solidified directionally

An influence of the liquid motion on the back-diffusion phenomenon has been studied in the case of directional growth of the Al-3.5Li alloy in both mi crogravity and terrestrial conditions. The Bridgman system has been used in both considered situations and conditions of solidification were similar. The definition of back-diffusion parameter known in Brody & Flemings theory has been applied. A new theory for the microsegregation formulated by Wolc zynski & Kloch has been used. It allowed for the description of the solute concentration within the liquid for which complete mixing has been assumed. A new equation for solute redistribution after back-diffusion within the s olid has also been applied. An estimation of back-diffusion parameter on th e basis of solute redistribution measurement for both experiments in extrat errestrial space (without the liquid motion) and in terrestrial laboratory (with convection in the liquid) has been made. Additionally, solute diffusi on within the solid has been estimated.