Abstract:Based on the configuration design through ball milling and vibration mixing method, the heterogeneous TiB2/Cu composites a harmonic structure containing the TiB2 rich zone (hard zone) and the pure Cu zone (soft zone) were prepared by hot pressing sintering. The effect of spherical Cu particle size on the microstructure, conductivity and mechanical properties of heterogeneous composite was studied. The results showed that when the spherical Cu particle size was small, the harmonic structure was not obvious, and the strength and plasticity was poor. When the spherical Cu particle size was larger than 15 μm, the harmonic structure was gradually obvious. When the spherical Cu particle size was in the range of 53~75 μm, the relative density and conductivity of the composite was the highest, and the incompatibility deformation between TiB2 rich zone and pure Cu zone helped to generate back stress in pure Cu zone to strengthen it, and the corresponding normal stress in TiB2 rich zone to toughen it. The combined effect of back stress and normal stress made the hard zone and soft zone of the harmonic TiB2/Cu composite exert better coordination deformation ability, which resulted in a better combination of strength and plasticity. With the further increase of spherical Cu particle size, the strength and plasticity of the composite decreased gradually. Therefore, it was very important to regulate an appropriate heterogeneous structure in the composite.