Abstract:In the production of AlCuFe alloy for a special application, the growth rate was changed and the results were evaluated. Changes in the eutectic spacing (microstructure) of a material due to the growth rate are known to affect its mechanical, electrical and thermal properties. To evaluate its microstructure, the eutectic composition of Al-32.5wt.%Cu-0.5wt.%Fe was prepared and directional solidification experiments were conducted using a Bridgman-type furnace at a constant temperature gradient (G=8.50 K/mm) and five growth rates (V=8.25, 16.60, 41.65, 90.05, 164.80 μm/s). The effect of the growth rate on the eutectic spacing was then determined, and the resulting microhardness and ultimate tensile strength were obtained based on the change in the microstructure by regression analysis and Hall-Petch correlations. Despite the fact that the growth rate increased by approximately twenty times, the eutectic spacing decreased by a factor of approximately 5, and these changes in the growth rate and microstructure caused the mechanical properties to change by a factor of approximately 1.5.

Key words: directional solidification; aluminum alloy; microstructure; tensile strength; hardness