Effect of diamond particle size on thermophysical properties of diamond /Cu-B alloy composites

Using copper-boron alloy as the metal matrix and different-sized diamond particles through 110 μm, 230 μm to 550 μm as reinforcement, the diamond/copper-boron alloy composites were prepared via gas pressure infiltration technology under 1100 ℃ and 10 MPa gas pressure. The influences of the size of diamond particles on the configuration, interlayer phase distribution, and thermophysical properties of the composites were investigated. The results show that with the increase of particle size, there is a benefit of better interface bonding, and the thermal conductivity of the diamond/copper-boron composite is enhanced while the thermal expansion coefficient decreases. When the diamond particle size is 500 μm, the best performance of the composite is obtained. The thermal conductivity is 680.3 W/(m·K), and the thermal expansion coefficient increases from 4.095×10−6 K−1 to 7.139×10−6 K−1.