Fabrication and thermal conductivity of copper matrix composites reinforced by tungsten-coated carbon nanotubes

Jun-hui Nie 1),Cheng-chang Jia 1),Xian Jia 1),Yi Li 1,2),Ya-feng Zhang 1),and Xue-bing Liang 1) 1) School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China 2) China Iron & Steel Research Institute Group,Beijing 100081,China

摘 要：Carbon nanotubes（CNTs） were coated by tungsten using metal organic chemical vapor deposition.Magnetic stirring was employed to disperse the W-coated CNTs（W-CNTs） in a Cu matrix,and then,the mixed powders were consolidated by spark plasma sintering.The W-CNTs obtained a uniform dispersion within the Cu matrix when the W-CNT content was less than 5.0vol%,but high content of W-CNTs（10vol%） resulted in the presence of clusters.The W-CNT/Cu composites containing low content of W-CNTs（<5.0vol%） exhibited a higher thermal conductivity than the sintered pure Cu,while the CNT/Cu composites exhibited no increase in thermal conductivity after the incorporation of uncoated CNTs.The W-CNT content was found to play a crucial role in determining the thermal conductivity of the W-CNT/Cu composites.The thermal conductivity of the W-CNT/Cu composites increased first and then decreased with the W-CNT content increasing.When the W-CNT content was 2.5vol%,the W-CNT/Cu composite obtained the maximum value of thermal conductivity.The thermal resistance of the（W-CNT）-Cu interface was predicted in terms of Maxwell-Garnett effective medium approximation,and its calculated value was about 3.0×10-9m2·K·W-1.

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