Investigation of the Some Physical Properties of the Directionally Solidified Al-Cu-Co Ternary Eutectic Alloy

Abstract

The Al-23.9% Cu-1.2% Co (wt%) ternary eutectic alloy was prepared using a vacuum melting furnace and a casting furnace. The samples were directionally solidified upwards at a constant growth velocity (18.8 mu m/s) under different temperature gradients (1.23-5.66 K/mm) and at a constant temperature gradient (5.66 K/mm) under different growth velocities (8.3-166 mu m/s) in a Bridgman-type directional solidification furnace. The dependence of the eutectic spacing on the solidification parameters (temperature gradient and growth rate) and that of the microhardness and compressive strength on the eutectic spacing and solidification parameters were investigated. The electrical resistivity measurements of the studied alloy were performed and the temperature coefficient of the resistivity was calculated from the curve of the resulting rho-Icurrency sign plot. The thermal conductivities of the sample grown at a constant temperature gradient and growth rate were obtained using the Wiedemann-Franz and Smith-Palmer equations.