Fabrication of Carbon Nanotube Reinforced Aluminum Matrix Composites via Friction Stir Processing

摘要

In this study, CNTs reinforced pure Al, 6061A1 and 2009A1 composites with uniformly dispersed CNTs were successfully fabricated by a combination of powder metallurgy and subsequent multi-pass friction stir processing (FSP). As the FSP pass increased, the CNT clusters were broken down due to the shear flow of the Al matrix during FSP, however, the CNTs were cut short. After 4-pass FSP, the CNTs were individually dispersed in the aluminum matrix along grain boundaries resulting in a much finer grain size. Although the CNTs were shortened and some Al_4C_3 formed in the matrix, the layer structures of the CNTs were well retained and the CNT-Al interface was good bonded. Compared to the Al matrix, the strength, especially the yield strength of the composites increased significantly.