Damping characteristic of Ni-coated carbon nanotube/copper composite

In this paper, the damping capacity and mechanical strength of Ni-coated carbon nanotube (CNT) reinforced copper-matrix nanocomposites (Ni-coated CNT/CMNc) and single-crystal copper are investigated using molecular dynamics (MD). It is found that the mechanical strength of copper can be significantly improved by the embedded Ni-coated CNT. However, a relatively higher dissipation rate is observed for the Ni-coated CNT/CMNc compared with single-crystal copper. To have a better understanding of the augmented dissipation rate for Ni-coated CNT/CMNc, the effects of oscillation frequency and temperatures on the quality factor (Q factor) are explored. The simulation results show that the Q factor decreases with the increase in angular frequency or temperature for both single-crystal copper and Ni-coated CNT/CMNc. In addition, a weaker frequency and temperature dependence is obtained for the case of Ni-coated CNT/CMNc compared with single-crystal copper. Furthermore, by tracing the source of dissipated energy, we demonstrate that the distorted Cu lattice structure caused by the attraction of Ni is the dominant factor for the high damping rate of Ni-coated CNT/CMNc. (C) 2017 Elsevier Ltd. All rights reserved.