Research On Preparation, Microstructure And Properties Of Carbon/Carbon-Copper Composites

Abstract:High pressure aided molten infiltration has been successfully used to fabricate C/C-Cu composites. The microstructure and properties of C/C-Cu composites, including electrical resistivity, thermal conductivity, mechanical properties and tribological property, wereinvestigated. The results are as follows:(1) Cu alloy is fully filled and well dispersed in C/C substrate. Good interface between Cu alloy and pyro-carbon or resin carbon is also observed. The infiltration route and distribution of Cu alloy are largely determined by the types of C/C substrate.(2) C/C-Cu composites with unidirectional fiber felt/net-like chopped fiber felt integrated needled fabric have better mechanical properties than those with net-like chopped fiber felt integrated needled fabric. However, the latter owns better electrical performance, thermal conductivity and tribological property (the line wear rate is only12mm/10000Km). Dominant wear mechanisms are oxidation wear and adhesion wear, respectively.(3) As the density of C/C substrate increases, the wear rates of C/C-Cu composites decreases successively as well as porosity, electrical performance and thermal conductivity while the overall mechanical properties increase. C/C-Cu composites with C/C substrate of which density about1.44g/cm3have the lowest wear rate of39.30/10000Km and24.90grms/10000Km. The main corresponding wear mechanisms are arc erosion wear, abrasive wear and the both.(4) With the increasing heat-treatment temperature of C/C substrate possessing resin carbon, the graphitization degree, electrical performance and thermal conductivity of C/C-Cu composites increase while the overall mechanical property decrease. The wear rates are36.60mm/10000Km and22.80grms/10000Km, coming to the lowest when C/C substrate treated at2300℃. The wear mechanism is transformed from abrasive wear to fatigue wear.(5) It can be concluded that the comprehensive property of C/C-Cu composites can be effectively increased when the C/C substrate with unidirectional fiber felt/net-like chopped fiber felt integrated needled fabric and pyro-carbon has been treated at a certain high temperature.