Influence of CNTs addition on the mechanical, microstructural, and corrosion properties of Al alloy using spark plasma sintering technique

Monolithic aluminium 1000 alloy is used in overhead transmission conductors because of its light weight, high electrical conductivity and high passivation property. But its low strength is a very big challenge to this application. However, the strength can be improved by proper reinforcement in a way that will not compromise other properties. So, this work was focused on improving the strength and corrosion properties of Al alloy with carbon nanotubes (CNTs) using spark plasma sintering (SPS). The start-up powders were blended with tubular mixer and sintered with SPS technique. The densities, microhardness and corrosion characteristics of the sintered samples were determined accordingly. Results obtained showed that there was a homogeneous dispersion of CNTs in the Al matrix of all the samples except Al-8CNTs. Al-4CNTs gave the highest microhardness of 482.60 +/- 12 MPa which represented 27% improvement in relation to monolithic Al alloy. Again, Al-4CNTs gave the least corrosion rate of 0.26723 mm/year in NaCl medium and 0.24188 mm/year in H2SO4 medium (46% and 47% improvements, respectively). These results indicate that Al-CNTs composite is a robust material for high transmission conductors.