TY - JOUR
T1 - Atomistic simulation study of brittle failure in nanocrystalline graphene under uniaxial tension
AU - Cao, Ajing
AU - Qu, Jianmin
PY - 2013/2/18
Y1 - 2013/2/18
N2 - We show that, using molecular dynamic simulations, nanocrystalline (NC) graphene fails by brittle fracture along grain boundaries under uniaxial tension at room temperature. Initiated from either a grain-boundary triple junction or an array of vacancies on a preferential grain boundary, fracture occurs by unzipping atomic bonds along a preferential grain boundary. In sharp contrast to NC metals, no mobile dislocations are generated throughout the entire loading process, and the deformation remains fully elastic (albeit nonlinear) until the breaking of the first atomic bond due to high local stress near the initiation defect sites. Breaking of the first atomic bond triggers a cascade of bond breaking events along a preferential grain boundary that leads to the final brittle fracture failure. For the NC graphene monolayer sheet with an average grain size of ∼25 nm considered here, the predicted uniaxial tensile strength is 96.2 ± 4.2 GPa, which is one of the highest among all polycrystalline materials.
AB - We show that, using molecular dynamic simulations, nanocrystalline (NC) graphene fails by brittle fracture along grain boundaries under uniaxial tension at room temperature. Initiated from either a grain-boundary triple junction or an array of vacancies on a preferential grain boundary, fracture occurs by unzipping atomic bonds along a preferential grain boundary. In sharp contrast to NC metals, no mobile dislocations are generated throughout the entire loading process, and the deformation remains fully elastic (albeit nonlinear) until the breaking of the first atomic bond due to high local stress near the initiation defect sites. Breaking of the first atomic bond triggers a cascade of bond breaking events along a preferential grain boundary that leads to the final brittle fracture failure. For the NC graphene monolayer sheet with an average grain size of ∼25 nm considered here, the predicted uniaxial tensile strength is 96.2 ± 4.2 GPa, which is one of the highest among all polycrystalline materials.
UR - http://www.scopus.com/inward/record.url?scp=84874530180&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84874530180&partnerID=8YFLogxK
U2 - 10.1063/1.4793088
DO - 10.1063/1.4793088
M3 - Article
AN - SCOPUS:84874530180
SN - 0003-6951
VL - 102
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 7
M1 - 071902
ER -