ATOMIC SIMULATION ON DEFORMATION AND FRACTURE OF NANO-SINGLE CRYSTAL OF NICKEL IN TENSION

Citation
T. Kitamura et al., ATOMIC SIMULATION ON DEFORMATION AND FRACTURE OF NANO-SINGLE CRYSTAL OF NICKEL IN TENSION, JSME international journal. Series A, Solid mechanics and material engineering, 40(4), 1997, pp. 430-435
Citations number
10
Language
INGLESE
art.tipo
Article
ISSN journal
1344-7912
Volume
40
Issue
4
Year of publication
1997
Pages
430 - 435
Database
ISI
SICI code
1344-7912(1997)40:4<430:ASODAF>2.0.ZU;2-6
Abstract
In order to elucidate the mechanism of deformation and fracture of mic rocomponents, numerical simulations are conducted for a nanoscopic wir e and film of nickel without lattice defects on the basis of a molecul ar dynamics using the EAM (embedded atom method) potential. A bulk of nickel is also treated by applying a periodic boundary condition for c omparison. These materials are subjected to a tensile strain along the [001] direction of the fee (face-centered cubic) lattice. Here, the t ransverse stresses in the bulk material are kept at zero during tensio n. The yielding is brought about by the crystallographic slips on the (111) planes and there is little difference in the yield stress among the wire, film and bulk. The slips continue to take place on multiple (111) planes and the plastic deformation leads to ductile fracture. Ne xt, the displacement in the transverse direction on the cell boundarie s of the bulk is fixed in order to investigate the effect of constrain t. It shows brittle fracture due to cleavage cracking. This implies th at the constraint, which may be introduced by local inhomogeneity of t he material, brings about early crack nucleation and reduces the ducti lity of materials without lattice imperfection.