Microstructure and Properties of Dilute Cu-Nb Alloy Prepared by Mechanical Alloying

This paper presents the synthesis of a Cu-0.5wt%Nb alloy via mechanical alloying (MA) and subsequent hot pressing. The evolutions of the density, microstructure, microhardness and electrical conductivity of the alloy as a function of the sintering temperatures were investigated. The results show that the microhardness of the alloy decreases with increasing consolidation temperatures, while the density and the conductivity improve. The alloy, subjected to vacuum hot-pressing sintering under 25 MPa pressure and 800 °C for 2h, has a microhardness of 102 HV and an electrical conductivity of 98% IACS. The as processed alloy is characterized by Nb nanoparticles distributed in the submicron sized Cu grains. The microhardness and electrical conductivity of the alloy are closely related with the microstructure, i.e. Cu grain size, as well as the presence and distribution of Nb nanoparticles.