Modification of Al alloy nanopowder with Nb nanopowder on its thermal and tribological properties with SPS for power conductors

Al 1000 alloy has high purity and good electrical conductivity required for high power transmission conductors but lacks adequate thermal and tribological properties necessary for optimal performance and durability. To augment these properties, Nb nanopowder was incorporated into Al base metal and consolidated with spark plasma sintering (SPS). The SPS was conducted with pre-optimized processing parameters of 630 °C temperature, 30 MPa pressure, 10 min holding time and 200 °C min^-1 heating rate. 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 and tribological testing. A laser flash analysis (LFA) and thermogravimetric analysis (TGA) were used in the thermal test while ball-on-disc tribometer was used in the tribology test. Results obtained showed that Al-4Nb had the highest thermal conductivity of 115. 95 6.9 Wm^-1K^-1 which represented 42% improvement. The same sample had best tribology characteristics with 45% improvement in coefficient of friction (COF), 20% improvement in both wear volume and wear rate. So, it follows that Al-Nb composite is a better replacement for monolithic Al 1000 alloy in power transmission conductors with a potential property of low sag and high wear resistance during operation.