Enhanced thermal conductivity of diamond/copper composite fabricated through doping with rare-earth oxide Sc2O3

Diamond/copper composite has been considered as one of the next generation thermal management materials. Interfacial modification is an essential means of ameliorating interface wettability and bonding of diamond/copper composite for improving its thermal conductivity . In the present work, Diamond/copper composite was manufactured by using spark plasma sintering (SPS) technology with 60% volume fraction of diamond mixed with 40% volume fraction of copper power, chromium powder (0.7 wt%) and scandium oxide powder (0.21 wt%). A series of material analysis methods were used to characterize the microstructure, interfacial layer , phase compositions and distributions of Diamond/copper composite. The total and partial electron density of states (DOS) for Diamond-Cr-Sc 2 O 3 interfacial model was investigated by means of first-principles calculations from CASTEP modules. The results showed Sc 2 O 3 made a 5–20 nm well-arranged and uniformly distributed interfacial chromium carbide layer in the interface region, which played a critical role in increasing the amount of reactive interfacial bonding and decreasing defect. The addition of Sc 2 O 3 brought the increasing number of heat transfer carriers at the interface and made the interface energy system more stable. The obtained diamond/copper composite exhibited that the wettability between diamond particles and copper was effectively improved. The thermal conductivity of diamond/copper is 872 W/(m·K) and the possible reasons for doping rare-earths Sc 2 O 3 to improve the thermal conductivity were discussed.