Thermal conductivity and thermal expansion coefficient of diamond/5 wt%Si-Cu composite by vacuum hot pressing

For prepared diamond/5 wt%Si-Cu composite materials by vacuum hot pressing, the microstructure and properties of composite materials were studied. The results show that relative density, coefficient of thermal expansion and thermal conductivity of the composite decrease with the increase in diamond content (0-20 vol%). Using 120/140 mesh diamond of 5% (volume fraction), the diamond/5 wt%Si-Cu composite was hot pressed at 1000 oC under pressure of 25.5 MPa in a vacuum for 10 min. Its relative density is up to 96%, thermal conductivity is 455 W/m K, as well as average coefficient of thermal expansion (20-600 oC) is 27 x 10-6/oC.