Effect of NbC volume fraction on mechanical properties of ultrafine grained Cu-NbC nanocomposites

摘要

Ultrafine grained (UFG) Cu-NbC nanocomposites with 3.2, 6.4 and 9.5vol% in-situ formed NbC nanoparticles were fabricated by a combination of high energy mechanical milling, heat treatment and hot extrusion. The microstructure and mechanical properties of the samples were investigated to establish the NbC volume fraction-mechanical properties relationship. It is shown that 6.4vol% is the best among the three NbC volume fractions for achieving the highest tensile strength (869 MPa) and a good ductility (elongation to fracture: 6.0%) of the UFG Cu-NbC nanocomposites. The microstructural reasons for the optimum properties are analyzed.