Interface analysis of ultra-high strength carbon nanotube/nickel composites processed by molecular level mixing

Carbon nanotube (CNT) reinforced nickel matrix (CNT/Ni) composites exhibiting a yield strength (YS) of 710 MPa, about 3.7 times higher than monolithic nickel, have been processed by a molecular-level mixing process followed by spark plasma sintering (SPS). The enormous strength increase in these composites can be attributed to a homogeneous distribution of nanotubes in the nickel matrix coupled with the formation of well-bonded, high strength, contaminant-free nanotube/nickel interfaces, as revealed by high-resolution transmission electron microscopy. Such interfaces can effectively transfer load between nanotubes and nickel matrix in the CNT/Ni composites. (C) 2013 Published by Elsevier Ltd.