Influence of Ti content on microstructure and thermal conductivity of diamond/cu composites fabricated by spark plasma sintering

The microstructure and thermal conductivity of diamond/Cu composites with varying Ti contents are investigated. Without Ti, weak mechanical bonding and interfacial porosity severely impede heat transfer. The introduction of Ti promotes interfacial reactions with diamond to form a TiC layer that enhances interfacial bonding and increases relative density. Excessive Ti content, however, leads to the formation of thicker TiC layer and the presence of residual Ti in the Cu matrix, which increase interfacial thermal resistance. The optimal performance is obtained at 0.6 wt% Ti, yielding a continuous TiC layer of ∼400 nm and a maximum thermal conductivity of ∼704 W·m⁻¹·K⁻¹.