Improving the mechanical behavior of an ultrafine grained Cu-6.4vol.%NbC nanocomposite by hot rolling

Abstract

To improve the mechanical behavior of the ultrafine grained Cu-6.4vol.%NbC nanocomposite rods fabricated by powder compact extrusion, they were hot-rolled into sheets at 800 and 1000 °C respectively. Rolling at 800 °C caused the ultimate tensile strength (UTS) of the nanocomposite to clearly decrease from 868 to 755 MPa without changing the tensile ductility, while rolling at 1000 °C caused a similar change of the UTS, but increased the elongation to failure (ETF) of the nanocomposite drastically, from 6% to 12.6%. Such a significant improvement in ETF while still maintaining a high strength was ascribed to the elimination of the residual unconverted interparticle boundaries and the nanoparticle stablilized nanocrystalline microstructure.