Low-Temperature Transport Properties of Commercial Metals and Alloys. II. Aluminums

Abstract

The thermal conductivity, electrical resistivity, Lorenz number, thermoelectric force, and thermoelectric power are given in the temperature range 4–120°K for ten aluminums and aluminum alloys: high-purity, 1100-F, 1100-O, 3003-F, 2024-T4, 5052-O, 5083-O, 5086-F, 5154-O, and 6063-T5. Four of the samples show a maximum in thermal conductivity, the others do not. For the four high-thermal conductivity samples the separate components in the electronic thermal resistivity are resolved; for the others, components in both the electronic and the lattice thermal resistivities are given. The residual electrical resistivities vary from 2.5×10−8 to 3.2×10−6 ohm cm. The Lorenz numbers for the high-conductivity samples fall considerably below the Sommerfeld value 2.44×10−8 watt-ohm/°K2; those for the low-conductivity samples are somewhat above the Sommerfeld value. The thermoelectric power of some of the the alloys is positive with respect to the high-purity sample, for others it is negative. The various properties, methods of analysis, and separation of components are discussed in detail.