Experimental and theoretical analyses of the thermal conductivity of diamond /SiC composites with SiC matrix

Diamond/SiC composites with SiC matrix were prepared by using a liquid silicon infiltration method. The interface morphology and thermal conductivity of the composites have been analyzed by scanning electron microscopy (SEM), and a laser flash thermal conductivity test, respectively. The thermal resistance of the interface structures has been calculated by using the acoustic and diffusion mismatch models. After the addition of mono-sized SiC particles, an increased diamond content resulted in an increased thermal conductivity of the composites. After the addition of SiC with a graded mix-sized particle under fixed diamond content condition, although the residual Si content decreased, the thermal conductivity of the composites showed little changes. Furthermore, the thermal conductivity of the composites have been calculated by applying Cubic Structure (C-S) and Hasselman-Johnson (H-J) models. The result shows that the calculations based on the C-S model showed the best agreement with the experimental thermal conductivity of the experiments with the addition of mono-sized SiC particles compared to the results analyzed by the other calculation models. The calculations based on the H-J model showed the best agreement with the experimental thermal conductivity of the graded mix-sized SiC particles composites compared to results analyzed by the other calculation models.