The development of metal matrix composite materials reinforced with continuous carbon fibres with extremely high thermal conductivity and low thermal expansion


Project start:01.01.2007
Project end:31.12.2009
Programme:VEGA
Project number:2/7173/27
Institute position in the project:The only one project investigator
Project leader:Pavol Štefánik
Composite materials with Cu, Al and Mg based matrices with uniaxially aligned high modulus K1100 carbon fibres were prepared by gas pressure of molten metal into porous preform and characterized in terms of structure, thermal expansion and thermal conductivity in parallel as well as normal directions with respect to the fibre alignment. Carbide forming element, i.e. Cr and Al were added to Cu and Mg matrices in order to improve the interfacial bonding and better metal penetration into the preform. The thickness, uniformity and composition of chromium carbide layer formed at the surface of fibres were analysed. Mg was added to Al to avoid the detrimental Al4C3 forming. Strong anisotropy of properties was observed in all composites. Thermal conductivity as high as 699.8 W/(m.K) and the coefficient of thermal expansion as low as 0.8x10-6 K-1 were obtained in Cu0.2Cr-K1100 composite. Composites exhibit high structural stability that was not violated by different thermal cycling tests.
 
2096-T Composite prepared from continuous high-modulus carbon fibres Thornel K1100 with Cu matrix