부산대학교 도서관

Isotropic tension is simulated in nanoscale polycrystalline copper with 10 nm grain size using large-scale molecular dynamics. The nanocrystalline copper is fabricated on the computer by growing randomly oriented grains from seed sites in simulations cell. Constant volume strain rates of 10-8 to 10-10 are considered for systems ranging from 10-5 to 10-6 atoms using EAM interatomic potential for copper. The spacing between voids for room temperature single crystal simulations is found to scale approximately as l{approximately}0. 005 Cs/gamma, where Cs is the sound speed and gamma is the strain rate. Below strain rates of about 10-9, only one void is observed to nucleate and grow in the 10 nm polycrystalline simulation cell. The growth of small voids is simulated by cutting a void out of the simulation cell and repeating the isotropic expansion.