Thermal expansion and thermal conductivity of continuous carbon fibre reinforced copper matrix composites

Carbon fibre reinforced copper matrix composites in adequate quality are promising materials in the applications where the heat transport plays an important role e.g. as heat sinks for electric and electronic industry. Except good thermal conductivity also a low coefficient of thermal expansion is important. In order to produce the material in an economic manner the first approach used continuous PAN-type carbon fibres (Torayca T300). They have been continuously copper coated and unidirectional and cross-ply samples have been produced by diffusion bonding. The coefficient of thermal expansion and the thermal conductivity of the material have been investigated. Thermophysical properties have been measured in both, longitudinal and transverse directions to the fibre orientation. The results showed that the cross-ply Cu-CI MMC produced from the Torayca T300 fibres may be a suitable candidate for heat sinks because of its good thermophysical properties e.g. in-plane thermal conductivity (approximate to 145W/m.K), through-thickness conductivity (approximate to 50W/m.K), low density (approximate to 5g/cm(3)) and the low coefficient of thermal expansion (8-9x10(-6) K-1).