Effect of particle size on microstructure and properties of Cu-Cr2O3 composites prepared by supercritical water in situ oxidation

In this paper, three kinds of Cu-Cr2O3 composites with different particle sizes were prepared from Cu-0.67wt%Cr atomized alloy powder by supercritical water liquid phase in-situ oxidation (SW-LIO) through reduction and spark discharge plasma sintering (SPS). The structure and properties of the composites were systematically analyzed by X-ray diffractometer (XRD), scanning electron microscope (SEM), energy spectrometer, transmission electron microscope, electron backscattering diffraction, universal material testing machine, microhardness tester, eddy current conductometer, friction and wear testing machine, etc. The results show that Cr2O3 particles are evenly distributed in Cu matrix composites. The hardness of composites improved by 19% as the particle size decreased, while the tensile strength and electrical conductivity first increased as the particle size is refined. Meanwhile, the deformation behavior research is carried out, and the mechanical properties and electrical conductivity of composites are enhanced as the deformation amount increases.