Effects of morphological characteristics of graphite fillers on the thermal conductivity of the graphite/copper composites fabricated by vacuum hot pressing sintering

Graphite/Cu composites are promising thermal management materials due to their excellent thermal properties. This work provides an experiment and theoretical evaluation of effects of morphological characteristics of graphite fillers on the thermal conductivity of the composites. Various graphite fillers, such as particles, chopped fibers and flakes are coated with copper layer by electroless plating method, and then are incorporated into copper matrix by vacuum hot pressing sintering. Combined with the microstructural observation, a predictive models based on the effective medium approach is used to analyze the thermal conductivity behavior of graphite/Cu composites. The predicted values show a good agreement with the experimental results. The analyzing results show that the large size graphite flake is the most promising heat dissipation fillers for Cu matrix composites, due to the high TC in two-dimensional plane and the good orientation in matrix.