Atomistic Simulation Study on the Tensile Deformation Behaviour of Nanocrystalline Ni
Using molecular dynamics simulations,the influence of transverse tensile stresses on the plastic deformation behaviour of nanocrystalline (NC) Ni under tension has been investigated.The sample with an average grain size of 20 nm was created using a Voronoi construction,and two different tensile tests of the sample were performed at a constant strain rate.The simulation results revealed that more partials were emitted from the grain boundaries and propagate into the grain interiors after adding the transverse tensile stress,enhancing the dislocation density in the grain interiors.This increased dislocation density can cause additional strain hardening observed in the stress strain curve.Meanwhile,it was observed from microstructures that nanovoids are easier to form and coalesce into cracks under the biaxial stress state,causing strain softening.The two competing effects of the transverse tensile stress on the plastic deformation behaviour of NC Ni resulted in the flow stresses from 4% to 10% strain in the biaxial stress state slightly larger than those in the uniaxial stress state.
Nanocrystalline materials Molecular dynamics simulations Plastic deformation Stress states
Wenbin Li Fuping Yuan Xiaolei Wu
State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China
国际会议
the Chinese Materials Congress 2012(2012年中国材料大会(CMC2012))
太原
英文
315-320
2012-07-13（万方平台首次上网日期，不代表论文的发表时间）