Low-temperature heat conduction characteristics of diamond/Cu composite by high pressure infiltration

In order to study variation of the thermal conductivity of the diamond/Cu composite prepared by high pressure infiltration at low temperature zone, the diamond/Cu composites with different diamond particle sizes (100 μm, 250 μm and 400 μm) were separately prepared by high pressure infiltration (HPF) method, the scanning calorimetry was used to analyze and evaluate the thermal conductivity of the diamond/Cu composites at low temperature, and SEM was used to analyze the microstructure of the composites. The results show that the thermal resistance of diamond particles in the heat transfer of grain boundary is far less than that in the interfacial heat transfer, for part of the diamond in the diamond/Cu composites prepared by high pressure infiltration becomes involved in polycrystalline reaction. The inner deformation and crushing of diamond particles result in more defects under high pressure infiltration condition, and the heat transfer with phonons as the main heat carrier at low temperatures of 100-150 K is sensitive to such defects as crack and clearance. Therefore, the thermal conductivity of diamond/Cu composites prepared by high pressure infiltration method is lower than that of the composites prepared by common pressure infiltration (PF) method at low temperature.