The thermal conductivity of carbon-fiber reinforced metal matrix composites

High thermal conductivity metal matrix composites are being considered for heat sink applications in fusion energy, automotive and aerospace industries. The addition of P-120 carbon fibers was found to enhance the thermal conductivity of both aluminum and copper matrix composites. However, above 60 volume percent loading, the thermal conductivity of the composites tends to decrease. The titanium used as a fiber interface was found to be deleterious to the thermal conductivity of the copper matrix. Small diameter diamond particle additions tend to reduce the thermal conductivity of both the copper and aluminum matrix composites. This is explained in terms of the dominance of thermal boundary resistance due to the large surface to volume ratio of the small diamond particles.