Thermal-conductivity measurements and predictions for Ni-Cr solid solution alloys

Thermal conductivities of Ni-Cr solid solution alloys have been measured to develop a prediction equation for thermal conductivities as functions of temperature and chemical composition. Samples used were Ni-x at% Cr (0 ≤ x ≤ 22) and commercial alloys of Nichrome Nos. 1 and 2. Thermal conductivity measurements were carried out using the transient hot-strip method over a temperature range from 293 K to 1273 K. The thermal conductivities of the alloys increased with increasing temperature and decreased with increasing Cr concentration at constant temperature. The Smith-Palmer equation has been examined to relate the thermal conductivities of the alloys to the electrical resistivities. The thermal conductivity and electrical-resistivity data, respectively, in the present work and in the literature have confirmed that the Smith-Palmer equation applies to Ni-Cr solid solutions and Nichrome alloys. On the basis of this equation, the thermal conductivity of Ni-Cr solid solution alloys has been expressed as a function of temperature and chemical composition. This analysis has also been applied to Ni-Fe and Cu-Ni solid solution alloys.