Dependency of the thermal and electrical conductivity on the temperature and composition of Cu in the Al based Al–Cu alloys

The variations of thermal conductivity with temperature for Al–[ x] wt.% Cu, x = 3, 6, 15 and 24 alloys were measured by using a radial heat flow apparatus. The variations of electrical conductivity of solid phases versus temperature for the same alloys were determined from the Wiedemann–Franz and Smith–Palmer equations by using the measured values of thermal conductivity. From the graphs of thermal and electrical conductivity versus temperature, the thermal conductivity of the solid phases at their melting temperatures, and the thermal temperature and the electrical coefficients for the same alloys were obtained. Dependency of the thermal and electrical conductivity on the composition of Cu in the Al based Al−Cu alloys were also investigated. According to present experimental results, the thermal and electrical conductivity of Al–[ x] wt.% Cu, x = 3, 6, 15 and 24 alloys linearly decrease with increasing the temperature and composition of Cu. The enthalpy of fusion and the specific heat change during the transformation for the same alloys were determined from cooling trace during the transformation from eutectic liquid to eutectic solid by means of differential scanning calorimeter (DSC).