In this work, the synthesis and characterization of a rapidly solidified Al-Fe-Si-Zr alloy is presented. The rapidly solidified alloy ribbons were prepared using a melt spinning machine. The kinetics and sequence of microstructural changes during heating of the ribbons at a constant rate of 5 ⁰C/min were determined by scanning electron microscopy as well as on-line electrical resistivity measurements.
The microstructure of the rapidly solidified alloy ribbons is cellular. The cellular morphology of the solidification varies with the distance between the bottom surface and the top free surface. A nanocellular microstructure has formed on the bottom surface of the strip in contact with the roller, while a cellular and/or dendritic microstructure has formed on the top surface of the strip. The primary α-Al phase represents the interior of the cells. The cell walls, which form a continuous network, belong to the Al, Fe, and Si reach phases. The microstructural changes occurring during heating were detected and analysed by on-line electrical resistance measurements and electron microscopy. Two temperature intervals of changes were detected in the electrical resistivity measurements. The main microstructural change that occurred after heating beyond the first temperature interval was the deterioration of the cell structure. However, when heating beyond the second temperature interval, a process of growth and reshaping of particles in the α-Al matrix takes place. The process of microstructural change is relatively complex and occurs via intermediate metastable phases.
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