Reduced interlayer defects of diamond/copper composite doped with holmium (III) oxide

The interlayer defects of diamond/copper (Cr) composite have been eliminated by adding holmium (III) oxide through Spark Plasma Sintering (SPS) method. The effects of Ho2O3 addition of diamond–copper interlayer on the microstructure and phase composition are investigated. The total density of states (DOS) and partial density of states (PDOS) are investigated by the first-principles calculations. It is revealed that the addition of Ho2O3 has a distinct modification effect on diamond–copper (Cr) interlayer. Obvious cracks around the diamond outer surface are hardly found, and the diamond particles are enfolded by the copper matrix. The Cr2C phase that beneficial to reduce interlayer defects and improve interlayer bonding was generated under the effect of adding Ho2O3. The thermal conductivity of diamond/copper (Cr-Ho2O3) is 686 W/(m·K). The possible reasons for doping Ho2O3 to eliminate interlayer defects and improve the thermal conductivity were discussed.