Uniformly dispersed Y2O3 nanoparticles in nanocrystalline copper matrix via multi-step ball milling and reduction process

A Cu-10 vol% Y2O3 nanocomposite was successfully fabricated via a novel route, namely a multi-step ball milling and reduction process, using CuO and Y2O3 as raw materials. The copper matrix nanocomposite exhibited a high microhardness of HV209.6 (three times that of pure copper), high compressive 0.2% strength of 655 MPa (seven times that of pure copper), favourable ductility of 33.4% and good electrical conductivity of 53.8% IACS. The changes in phases and microstructure after different process steps were investigated. The result revealed that CuO particles were reduced nearly completely after the 2nd reduction process, and the crystallite size of copper remained in the nanoscale after the consolidation process. Furthermore, 10 vol% yttria nanoparticles were uniformly dispersed in the nanocrystalline copper matrix composite. (C) 2019 Elsevier B.V. All rights reserved.