Year-end Sale % OFF 
Abstract
In this present work, two methods for dispersing carbon nanotubes into the copper matrix were tested: a Solid Route process where CNTs are simply mixed with the copper powder and a Liquid Route process where CNTs are dispersed in a copper salt solution and then mixed with the metallic copper powder. Powders are sintered by uni-axial hot pressing process under vacuum atmosphere at 650°C and thermal conductivities of composite materials were measured using the laser flash method. Results are compared with a theoretical model of Nan et al. which enables to predict the thermal conductivity of materials containing CNTs. Comparison of experimental and theoretical results tends to prove that CNTs are 2D-randomly dispersed in a plane perpendicular to the pressing direction during uni-axial hot pressing process. Moreover, an increase of +7% of the thermal conductivity is shown for the composite material containing 1 vol. % of CNTs into the copper matrix.
Highlights
Since their discovery in 1991 by Iijima[1], carbon nanotubes are intensively studied
If we consider that the graphite layer on the top and on the bottom face of the pure copper pellet ranges from 0 μm to 12 μm, the average thermal conductivity of the pellet calculated -using the Vogt-Reuss model- is equal to 378 W.m-1.K-1
If we consider that the technique for sputtering graphite onto the surface of the composite materials is repeatable, we can consider that the measured thermal conductivities of the three-layers materials C/(Cu-Carbon Nanotubes (CNTs))/C are 6% lowered than the real materials (Cu-CNT) without graphite layers
Summary
Since their discovery in 1991 by Iijima[1], carbon nanotubes are intensively studied. Theory predicts huge mechanical (EYoung=1 TPa), thermal (3000 to 6000 W.m-1.K-1) and electrical (107 to 109 A.cm-2) properties to carbon nanotubes that makes them interesting as reinforcements in composite materials. The resulting composite material possesses better mechanical[2][3], thermal[4] and electrical[5][6][7] properties than the pure matrix. The thermal properties of Cu-CNTs composite material depend i) on the quality of the dispersion of carbon nanotubes into the matrix and ii) on the interface thermal resistance between the reinforcement and the matrix. Chu et al [12] [13] fabricated Cu-CNTs materials with a novel technique for dispersing carbon nanotubes into the matrix. Despite a relative good dispersion of the reinforcement, the thermal conductivity of the composite materials was lower than the copper reference. The use of a theoretical model, using an effective medium approach like the model of Maxwell-Garnett modified by Nan et al.[15] for composite materials containing CNTs, could be a solution
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
