Journal of Materials Processing Technology vol:104 issue:1-2 pages:133-144
During the EuroMIR'95 space flight four hypo-eutectic Al-Si alloy matrix composites with a SiC dispersion were made molten at different thermal gradients and solidified with a different cooling rate in the TITUS (Tubular furnace with Integrated Thermal analysis Under Space conditions) tube furnace. On comparison with the ground processed reference samples, it appears that the distribution of the particles in the molten zone is much more homogeneous in the zero gravity cast specimens. Also additional tests were performed in a high gradient furnace (ASPF - advanced solidification processing facility) and in a low gradient furnace to complement the results of the space processed samples. A higher temperature gradient, where the gradient is parallel to the direction of solidification and opposite to the gravity, gives less convection. A decrease in the cooling rate leads to larger dendrites and cells, and to a decrease of the homogeneity of the SiC particle distribution.