Solidification behaviors of the emulsified Al-4wt%Fe alloy powders

The emulsified Al-4wt%Fe alloy powders showed several different microstructures depending on the amount of undercooling such as Al₁₃Fe₄, Al_xFe primary intermetallic, Al-Al₃Fe or Al-Al₆Fe eutectics and α-Al cellular structure. The presence of these phases depends on a competitive growth mechanism, which was determined by the undercooling prior to solidification. The amount of undercooling of the powders was monitored by differential thermal analysis and was matched with the microstructures. The difference of the amount of undercooling which corresponds to the microstructures between the experiment and the previous value converted by the LKT theory was rationalized through the solidification behaviors. A microstructure selection map of Al-4Fe alloy powders for tailored solidification was also suggested.