Fabrication and mechanical/conductive properties of multi-walled carbon nanotube (MWNT) reinforced carbon matrix composites

摘要

Multi-walled carbon nanotube (MWNT) reinforced carbon matrix (MWNT/C) composites have been explored using mesophase pitch as carbon matrix precursor in the present work. Results show that carbon nanotubes (CNTs)can enhance the mechanical properties of carbon matrix significantly. The maximal increment of the bending strength and stiffness of the composites, compared with the carbon matrix, are 147 percent and 400 percent, respectively. Whereas the highest in-plane thermal conductivity of the composites is 86 W m~(-1) K~(-1) which much lower than that of carbon matrix (253 W m~(-1) K~(-1)).At the same time the electrical resistivity of the composites is much higher than that of matrix. It is implicated that CNTs seem to play the role of thermal/electrical barrier in the composites. FSEM micrograph of the fracture surface for the composites shows that the presence of CNTs restrains the crystallite growth of carbon matrix, which is one of factors that improve mechanical properties and decrease the conductive properties of the composites. The defects and curved shape of CNTs are also the affecting factors on the conductive properties of the composites.