Investigation of the thermo-electrical properties of A707 alloys

Highlights: • K of the A707 alloy decreases from 154 to 124 W/m K with increasing temperature. • The α_TCC value for the studied alloy was determined to be -4.17 × 10⁻⁴ K. • The σ of A707 alloy exponentially decreases with increasing temperature. • Thermal diffusivity decreased from 61.6 × 10⁻⁶ to 50.2 × 10⁻⁶ m²/s with increasing T. -- Abstract: In the present work, the thermal conductivity, electrical conductivity, enthalpy of fusion, specific heat capacity and thermal diffusivity of the A707 alloy (Al–4.5 Zn–1.2 Mg–0.15 Cr–0.15 Zr wt.%) have been investigated. Phase identification of the studied alloy was investigated with energy dispersive X-ray analysis and X-ray diffraction techniques. Thermal conductivity of as-cast A707 alloy was measured using Comparison Cut Bar Method in the temperature range of 300–800 K. With the increase of temperature, thermal conductivity decreased gradually in as-cast A707 alloy. The electrical conductivities of the sample were obtained with the Wiedemann–Franz equation by using the measured thermal conductivity values. Thermal conductivity coefficients for the alloy were obtained from the graphs of thermal conductivity versus temperature. The enthalpy of fusion and the specific heat capacity during the transformation were also determined. Thermal diffusivity changes were calculated as a function of temperature through the obtained thermal data.