Novel interfacial modification for enhancing thermal properties of TiC @diamond/Cu composites

Diamond/Cu composites are promising for thermal management but their poor wettability requires carbide coatings for interfacial modification. This work proposes a novel magnesiothermic reduction method for synthesizing TiC @diamond at low temperatures utilizing a MgCl2–KCl molten salt system with TiO2 as the Ti source. An ∼325 nm TiC coating forms on diamond at 750 °C for 2 hours without graphitization. Interfacial analysis shows a semi-coherent interface with specific crystallographic orientations ([110] TiC // [110] diamond, (1 − 1−1) TiC // (1 − 1−1) diamond). The TiC @diamond/Cu composite shows optimal performance: thermal conductivity (TC) of 689 W/(m · K), 63% International Annealed Copper Standard electrical conductivity and 98.55% relative density, representing increases of 280.66% in thermal conductivity, 90.91% in conductivity and 8.02% in relative density compared to uncoated composites. Its CTE (Coefficient of Thermal Expansion) at 300 °C drops from 17.98 × 10−6 to 6.92 × 10−6/K, a 61.5% relative reduction, significantly enhancing thermal dimensional stability.