The Influence of Convection on Non-Equlibrium Solidification of Silver-Germanium alloys

Abstract

The hypo- and hypereutectic alloys of typical anomalous silver-germanium eutectic system have been solidified under both terrestrial and space conditions with the goal to create distinct convective flow levels in system. A special arrangement during crystallization has been used to decrease the inluence of oxide particles in the melt on nucleation process. The convection has been found to affect strongly nucleation and growth processes of both primary crystals and eutectic. Significant differeces have been observed in morphology and in solute segregation in microstructural components. The obtained results show much greater departure of solidifying system from equilibrium in the case of limited mobility of components (limited convection). In this way, the space conditions provide valuable enviroment to understand processes between equilibrium solidification of alloys and their transition into glassy state.