Facile mechanical fabrication of Cu-Ni/CNT nanocomposite for improved microstructural, hardness, and electrical characteristics

Cu-Ni/CNT nanocomposites with varying quantities of carbon nanotubes (CNTs) were synthesized via mechanical alloying. Subsequently, the nanocomposite powders were consolidated through cold pressing and sintering. The microstructure, CNT distribution, hardness, and electrical properties were evaluated using XRD, FESEM, hardness testing, and the four-point probe techniques. A homogeneous Cu-Ni alloy with an average particle size of 30 nm was obtained after 10 h of ball milling. Addition of 5 wt.% CNTs resulted in a significant 21.5% increase in density, a notable 142.9% enhancement in macro-hardness, and over 50% reduction in electrical resistivity. Optical micrographs demonstrated that CNT incorporation effectively inhibited matrix grain coarsening, corroborated by microhardness measurements indicating uniform CNT distribution within the copper-nickel matrix, facilitated by the milling process.