Electrical conductivity, mechanical strength and corrosion characteristics of spark plasma sintered Al-Nb nanocomposite

An experimental study of the microstructure, electrical conductivity, corrosion characteristics and mechanical strength of Al-Nb nanocomposite consolidated via spark plasma sintering was the focus of this work. The start-up powders as well as the sintered samples were characterised with X-ray diffractometer, transmission electron microscopy and field-emission scanning electron microscope equipped with energy dispersive X-ray spectroscopy. The microhardness of the sintered samples was tested with Vickers hardness tester. The polarisation test was carried out with Potentiostat Autolab. The electrical conductivity was tested with four-point probe meter. The microstructural results showed homogenous dispersion of Nb reinforcement in the matrix, no grain growth and absence of voids. Good corrosion characteristics were achieved with Al-1Nb and Al-4Nb composites while the highest microhardness of 420MPa and tensile strength of 138MPa were obtained with Al-4Nb. The electrical conductivity increased from 38.9 to 40.1% IACS with Al-8Nb. The improved properties were as a result of the optimal sintering parameters, good fabrication attributes of SPS and the synergistic effects of Al and Nb.