Thermal properties of aligned carbon nanotube/carbon nanocomposites

2020-01-23 12:23:19

composites thermal carbon phonon ACNT

责任者: Qian-Ming Gong;Zhi Li;Xiao-Dong Bai;Dan Li;Yun Zhao;Ji Liang 单位: Dept. of Mech. Eng., Tsinghua Univ., Beijing, China 来源出处: Materials Science Engineering A (Structural Materials: Properties, Microstructure and Processing)(Mater. Sci. Eng. A, Struct. Mater., Prop. Microstruct. Process. (Switzerland)),2004/10/25,A384(1-2):209-14 摘要: Aligned carbon nanotube/carbon (Acnt/C) nanocomposites were fabricated with traditional chemical vapor infiltration (CVI) technology. Thermal conductivities of as-deposited and graphitized samples were tested by laser flash method. Results show that although only half the density and half the fraction of reinforcing element compared with carbon/carbon (C/C) composites in this work, the thermal diffusivity of Acnt/C is generally 3-5 times that of C/C composites, and the thermal conductivity of lower density Acnt/C (about 0.8 g/cm3) samples can reach 72.24 W/m K, about 12.31% higher than C/C composites with higher density (about 1.50 g/cm3). Heat transfer mechanism analyses show that the potential superiority of thermal conduction for Acnt/C can be ascribed to the long wrapped graphene layers of well-aligned carbon nanotubes, which can reduce phonon-phonon Umklapp scattering along the axial direction largely. The gap between predicted and measured thermal conductivity of Acnt/C suggests the demand for CNTs with virtually good thermal conducting capability and pyrocarbon with better properties by regulating CVI process 关键词: carbon nanotubes;heat transfer;nanocomposites;phonon-phonon interactions;thermal conductivity;thermal diffusivity;umklapp process;thermal properties;aligned carbon nanotube/carbon nanocomposites;chemical vapor infiltration;CVI;thermal conductivity;graphitized samples;laser flash method;thermal diffusivity;heat transfer;wrapped graphene layers;phonon-phonon umklapp scattering;pyrocarbon;C-C composites;CNT;carbon/carbon composites;C-C