Study on thermal conductivity and electrical resistivity of Al-Cu alloys obtained by Boltzmann transport equation and first-principles simulation: Semi-empirical approach

Boltzmann transport equation (BTE) and first-principle approaches are applied in the estimation of the thermal conductivity and electrical resistivity of Al-Cu alloys with varying Al-Cu ratios. The electronic transport properties of various Al-Cu alloys are predicted by solving the BTE using a relaxation time approximation (RTA). The theoretical results are estimated through fitting of experimental data. It is shown that the results correctly estimate transport property trends in terms of temperature and composition. The transport properties are also estimated using a semi-empirical method based on experimental electrical resistivity data. It is believed that the primary reason for deviations between the experimental and theoretical values is computational limits arising from a lack of rigor in taking scattering effects and structural stability into account. This explanation for the deviation is also supported by the WF law and relaxation times (or scattering rate).