Thermal-Conductivity Measurements and Predictions for Ni–Cr Solid Solution Alloys

Abstract

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.