Investigation of the Thermal and Electrical Properties of Al-1.9Mn-xFe Ternary Alloys

In this work, the thermal conductivity, electrical conductivity, enthalpy of fusion, specific heat capacity and thermal diffusivity of the Al-1.9Mn-xFe ternary alloys (x: 0.5, 1.5 and 5.0 wt %) have been investigated. Thermal conductivity of as-cast Al-1.9Mn-xFe alloys were measured using comparison cut bar method in the temperature range of 323-823 K. Variation of electrical conductivity with the temperature in the range of 290-580 K for studied alloys was also measured by using a standard four-point probe technique. With the increase of temperature and Fe content, thermal conductivity and electrical conductivity decreased gradually in as-cast Al-1.9Mn-xFe alloys. The thermal temperature coefficient (alpha TTC) and the electrical temperature coefficient (alpha ETC) were calculated from the respective graphs. The electrical conductivities of the samples were predicted with the Wiedemann-Franz and Smith-Palmer equations by using the measured thermal conductivity values. The electrical conductivity values estimated from the Smith-Palmer equation were closer to the experimentally measured electrical conductivity values. 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. It was observed that thermal diffusivity values decreased with increasing temperature.