Molecular Dynamics Simulation of Mechanical Properties of Cu Nanowire with Grain Boundaries.

Abstract

Molecular dynamics (MD) is a computer simulation method for analyzing the physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a fixed period of time, giving a view of the dynamic "evolution" of the system. Material has inherent faults in the real life. Based on the molecular dynamics (MD) method, the single-crystalline copper nanowire with different surface defects is investigated through tension simulation. For comparison, the MD tension simulations of perfect nanowire are firstly carried. It has concluded that the surface-volume ratio significantly affects the mechanical properties of nanowire. It is found that the Young’s modulus is sensitive to surface defects. And the yield strength and yield point show a significant decrease due to the different defects. Different defects are observed to serve as a dislocation source.it is difficult to obtain lattice structure in real life. So defect in material structure persists among which grain boundary is prominent. In this thesis, we have conducted an MD simulation on copper with grain boundary to see its effect on mechanical properties. This study has provided a comprehensive and deep investigation into the mechanical properties of Cu NWs which can be helpful in determining the feasibility of practical applications of Copper in components of electrical devices compared to currently used materials such as Indium Tin Oxide. It has been exhibited by this study as well as the ones before it that MD simulation is an effective tool not only for the characterization of the properties of NWs, but also for the prediction of novel and unexpected properties