Stress relaxation behavior of annealed aluminum-carbon nanotube composite

Abstract

The mechanical properties and stress relaxation behavior of annealed aluminum-carbon nanotube composite were studied and compared with those of pure aluminum. The composite was prepared using an induction furnace, where 1.6 vol.% of multiwall carbon nanotubes were added in aluminum as strengthening material. It was found that the mechanical strength of the annealed composite was almost twice that of aluminum. The stress relaxation behavior of both materials was logarithmic in nature. However, the stress relaxation, hardening component, and intrinsic height of the thermally activated barrier were significantly influenced by the presence of nanotubes in the aluminum matrix. It was found that the stress relaxation rate of the composite was reduced (>30%) and the hardening component was increased (>100%) compared with that of aluminum. The calculated strengths of the thermally activated barriers for aluminum and the composite were 1.7 and 2.6 eV, respectively.