Fivefold enhancement of yield and toughness of copper nanowires via coating carbon nanotubes

Abstract

Carbon nanotubes are outstanding reinforcements owing to their unparallel strength, while their effects on the copper nanowire are still not fully understood, hampering their broad applications. Herein, we have investigated the tensile behaviors of the nanocomposite-wire of carbon nanotube-copper using molecular dynamic simulations. For the nanocomposite, both the coated and embedded carbon nanotubes increase the Young's modulus, fracture stress and toughness of the copper nanowire. A reinforcement of over fivefold in both yield strength (5.3 times) and toughness (5.1 times) has been achieved when the carbon nanotubes are coated on the copper nanowires, as well as 1.7 times in the Young's modulus. Higher temperatures and lower loading rates reduce the reinforcement.

Prediction of Temperature-Dependent Mechanical Properties for SWCNT/Cu Nanocomposite Metamaterials: A Molecular Dynamics Study

“…Moreover, all three Young’s moduli decrease with the increase in temperature. It is easy to understand the weakened loading bearing capacity of SWCNT/Cu nanocomposites caused by the expansion of distances of atoms and softened crystalline structure due to raised temperature [ 24 ]. It is easy to find that the enhanced effect in the x direction is more remarkable than those in the other two directions from Table 2 , that is because of the mechanical characteristics of the reinforcement SWCNT.…”

“…The adaptive intermolecular reactive empirical bond order (AIREBO) [ 42 ] potential with a cutoff radius ( r = 3 Å) is adopted for the force field between carbon atoms, which is widely employed to study CNTs [ 22 , 23 , 24 ]. The cohesive energy of this potential consists of three terms: in which E REBO , E LJ , and E TORSION are potential energy from short-ranged reactive empirical bond order (REBO) potential, standard Lennard-Jones (LJ) potential that adds longer-ranged interactions and the torsional interactions term that describes various dihedral angle preferences in hydrocarbon configurations.…”

“…To estimate the non-bonded interaction between copper and carbon atoms, we employ the LJ potential which has adequately predicted the Cu-C interaction and has been extensively used in the existing literature [ 22 , 23 , 24 , 25 ] on the MD study of carbon/copper molecular structures. The LJ potential energy is a function of the distance r ij between two atoms: in which ε and σ are the potential well depth and equilibrium interatomic distance, respectively.…”

“…where E Cu is the total energy for a pair of Cu atoms, F is the embedding energy which is a function of the atomic electron density ρ, ϕ is a pair potential interaction between atoms i and j separated by a distance r ij , and subscripts α and β are the element types of atoms i and j. Conventionally, we use 3.615 Å and 63.546 as lattice constant and atomic weight of copper, respectively. The adaptive intermolecular reactive empirical bond order (AIREBO) [42] potential with a cutoff radius (r = 3 Å) is adopted for the force field between carbon atoms, which is widely employed to study CNTs [22][23][24]. The cohesive energy of this potential consists of three terms:…”

“…Obviously, these experimental results are influenced by the processing method. In this case, an atomistic simulation like MD may be suitable for parametric investigations of the effects of composites and geometry on mechanical properties [ 22 , 23 , 24 , 25 , 26 ].…”