Influence of Solidification Parameters on the Amount of Eutectic and Secondary Arm Spacing of Al–7wt% Si Alloy Solidified under Microgravity

During the solidification of hypoeutectic Al–7% Si alloy, density differences develop in melt due to variations concentration and temperature. On Earth, flow can occur gravity, which then affects process. The microgravity environment strongly eliminates convection allows investigation process purely diffusive circumstances. In this study, four experiments were performed on grain-refined non-grain-refined Al–7 wt% alloy on-board International Space Station (ISS) Materials Science Lab (MSL) study effect parameters (solid/liquid front velocity (v) temperature gradient (G)) grain structure dendritic microstructure. has been analyzed detail some earlier studies. aim work was carry out detailed analysis macrosegregation caused by diffusion from initial mushy zone during homogenization step subsequent phase as well correlated distribution eutectic along direction. secondary dendrite arm spacing (SDAS) for different conditions also studied. For these two issues, experimental results compared simulation results. calculated finite difference method. Because steady-state never reached, characterized average gradient. Considering actual liquidus (TL) macrosegregation, SDAS a function processing with classical Kirkwood’s equation. As result, good agreement obtained between measured SDAS.