Interface and properties of copper matrix composites reinforced with TiC coated spherical graphite

The titanium-coated spherical graphite/copper (SGrT/Cu) composites was successfully produced by vacuum spark plasma sintering (VSPS) with the surface of spherical graphite (SGr) being modified via salt bath Ti plating. The microscopic morphology, fracture structure and phase composition were analyzed by scanning electron microscopy (SEM) and x-ray diffractometer (XRD). The influences of the TiC interfacial layer on bending strength, interface thermal resistance and thermal conductivity (TC) of the composites were systematically investigated. The results indicated that the densification behavior and bending strength of coated composites were improved compared to that of uncoated ones. The bending strength of the X-Y basal plane exhibiting 11%–23% increased by plating Ti treatment as against the unmodified one. However, the titanium-plated SGrT/Cu composite slightly decreased along the TC of the X-Y base plane. In view of the influence of TiC layer on TC, an effective medium approximation (EMA) model was introduced to predict the TC of the composites.