Electrical and thermal properties of Ti₃AlC₂ at high temperature

In this paper, we report on the electrical and thermal properties of predominantly single-phase Ti₃AlC₂ ceramics (96.7 wt%) as a function of temperature. The results show that Ti₃AlC₂ is a good electrical and thermal conductor at high temperature. From 300 to 1173 K, the electrical resistivity of Ti₃AlC₂ increases linearly from 3.4 × 10^-5 to 1.1 × 10 ^-4Ω·m, which indicates that Ti₃AlC ₂ ceramic is ametallic conductor. In the 473 to 1473K temperature range, the coefficient of thermal expansion of Ti₃AlC₂ yields an average value of 9.3 × 10^-6K^-1, which is comparable with the coefficients of Ti₂AlC and Ti₃SiC ₂. The thermal conductivity increases from 22.6 to 26.4W·m^-1·K^-1 with rising temperature from 473 to 1473 K. It is found that the electronic contribution to the thermal conductivity is the dominant mechanism. The molar heat capacity of Ti ₃AlC₂ is 138.6 J·mol^-1·K ^-1 at 473K and extrapolates to 168.5 J·mol ^-1·K^-1 at 1473 K.