Effect of Carbon Nanotube Orientation on Mechanical Properties and Thermal Expansion Coefficient of Carbon Nanotube-Reinforced Aluminum Matrix Composites  

作　　者：Z.Y.Liu B.L.Xiao W.G.Wang Z.Y.Ma 

机构地区：[1]School of Materials Science and Engineering,Dalian University of Technology [2]Shenyang National Laboratory for Materials Science,Institute of Metal Research,Chinese Academy of Sciences [3]School of Mechanical Engineering,Liaoning Shihua University

出　　处：《Acta Metallurgica Sinica(English Letters)》2014年第5期901-908,共8页金属学报（英文版）

基　　金：financially supported by the National Basic Research Program of China (Nos.2011CB932603 and 2012CB619600);the National Natural Science Foundation of China (No.51331008)

摘　　要：Carbon nanotube-reinforced 2009Al （CNT/2009Al） composites with randomly oriented CNTs and aligned CNTs were fabricated by friction stir processing （FSP） and FSP-rolling, respectively. The CNT/2009A1 composites with aligned CNTs showed much better tensile properties at room temperature and elevated temperature compared with those with the randomly oriented CNTs, which is mainly attributed to larger equivalent aspect ratio of the CNTs and avoidance of preferential fracture problems. However, much finer grain size was not beneficial to obtaining high strength above 473 K. The aligned CNTs resulted in tensile anisotropy, with the best tensile properties being achieved along the direction of CNT aligning. As the off-axis angle increased, the tensile properties were reduced due to the weakening of the load transfer ability. Furthermore, aligned CNTs resulted in much lower coefficient of thermal expansion compared with randomly oriented CNTs.Carbon nanotube-reinforced 2009Al （CNT/2009Al） composites with randomly oriented CNTs and aligned CNTs were fabricated by friction stir processing （FSP） and FSP-rolling, respectively. The CNT/2009A1 composites with aligned CNTs showed much better tensile properties at room temperature and elevated temperature compared with those with the randomly oriented CNTs, which is mainly attributed to larger equivalent aspect ratio of the CNTs and avoidance of preferential fracture problems. However, much finer grain size was not beneficial to obtaining high strength above 473 K. The aligned CNTs resulted in tensile anisotropy, with the best tensile properties being achieved along the direction of CNT aligning. As the off-axis angle increased, the tensile properties were reduced due to the weakening of the load transfer ability. Furthermore, aligned CNTs resulted in much lower coefficient of thermal expansion compared with randomly oriented CNTs.

关 键 词：Carbon nanotubes Metal matrix composites Mechanical properties Coefficient of thermalexpansion Friction stir processing 

分 类 号：TB333[一般工业技术—材料科学与工程] TB383