Atomistic simulations of interfacial mechanical characteristics of carbon nanotube/silicon nanocomposites

The interfacial mechanical properties of carbon nanotube (CNT)-reinforced silicon nanocomposites are investigated by using molecular dynamics simulation method. The hybrid potential that includes Tersoff-2 potential for Si-Si in the silicon matrix, AIREBO potential for C-C in the CNTs and the Lennard-Jones (LJ) potential for Si-C in the interface is used in the nanocomposite system. The effects of such parameters as the CNT chirality, the CNT diameter and the CNT embedded length, the defects (Vacancy defects, Stone-Wales defects), the size of model, the temperature, the bonding strength and the cut-off distance of the interfacial LJ potential of nanocomposites on the pull force and the average interfacial shear strength (ISS) are investigated and discussed. The results show that the toughness and the maximum tensile strength have been increased significantly by adding the CNTs into the Si matrix. Also by increasing the LJ bonding strength and the cut-off distance of the LJ potential, the pull force and the ISS are increased significantly. The CNT chirality, the CNT diameter and the CNT embedded length have a great influence on the pull force and the ISS, while the effects of temperature, the defects and the size of model are very slight.