Grain refinement assisted strengthening of carbon nanotube reinforced copper matrix nanocomposites

Carbon nanotube reinforced copper matrix (CNT/Cu) nanocomposites were fabricated by the modified molecular-level mixing process, which produces a homogeneous dispersion of CNTs in a fine grained metal matrix. These nanocomposites, consisting of 1.5 mu m Cu matrix grains and 5 vol % of multiwall CNTs, show a high strengthening capability; enhancing the yield strength of unreinforced Cu by 2.3 times. The enhanced yield strength stems from the reinforcing effect of CNTs and additional hardening of the Cu matrix by grain refinement. The results reveal that the metallurgical treatment of the matrix is important for the development of high-strength CNT/metal nanocomposites. (c) 2008 American Institute of Physics.