MD simulation of atom-order void formation in Ni fcc metal

Abstract

Atom-order void formation in a defective crystalline material is studied by using molecular dynamics method (MD). Infinite long cylinder, which is constructed with nickel atoms with a line of vacancies, is subjected to multiaxial tensile strain field by moving periodic boundary and the atoms on the outer surface of the cylinder. When the load exceeds a critical value, sudden appearance of the void is observed and it develops rapidly. The developed void does not disappear by only unloading and relaxation, in spite of the system with the void has higher potential energy than that without void. The biaxial or the triaxial load is necessary to the atom order void formation. Moreover, the results by the MD simulations are compared with theoretical solution for nonlinear elastic solid.