Improvement on the thermal conductivity of Diamond/CVI-SiC composites using large diamond particles

摘要

The Diamond/SiC composites were fabricated via slip casting and chemical vapor infiltration (CVI) approaches. The effects of diamond particle size (50-500 mu m) on microstructure, flexural strength, density, fracture toughness and thermal conductivity of Diamond/SiC composites were discussed. By using large-sized diamond particles, thermal conductivity of composites can be improved and the maximum value could reach up to 241 W/(m.k), which is 2.1 times higher than that of the Diamond/SiC composites prepared by tape-casting and CVI process. With increasing of diamond particle size, the density of Diamond/SiC composites increased, and the mechanical properties decreased. The maximal density, flexural strength and fracture toughness were 3.18 g/cm(3), 287 MPa and 5.0 MPa.m(1/2) respectively. The fracture mechanism of the composites transferred from diamond particles transgranular fracture to interfacial debonding. (C) 2017 Elsevier B.V. All rights reserved.