Thermal conductivity improvement of Al alloy with Nb nanopowder using SPS for transmission conductor

Abstract

Aluminium 1000 alloy has high purity and good electrical conductivity required for high power transmission conductors but lacks adequate thermal conductivity which induces sagging in service. To augment this deficiency, Nb nanopowder was incorporated into it as a reinforcement and consolidated with spark plasma sintering (SPS). The SPS was conducted with pre-optimized processing parameters of 630 °C, 30 MPa, 10 mine and 200 °C/min. The sintering was conducted in a vacuum with graphite die of 20 mm in diameter. Thereafter, the sintered samples were metallographically prepared and subjected to thermal conductivity testing. A laser flash analyzer was used to generate the thermal diffusivity of the samples. Then their thermal conductivities were computed. Results obtained showed that Al-4Nb had the highest thermal conductivity of 115. 95 ± 6.9 W/mK which represented 42% improvement. So, it follows that Al-Nb composite is a better replacement for monolithic Aluminium 1000 alloy in power transmission conductors with a potential property of low sag.