The molecular dynamics （MD） simulation and the modified analytical embedded-atom method （MAEAM） were used to study the influence of a He atom on the movement of the（a/2）？110？{111} edge dislocation in Ni. First...The molecular dynamics （MD） simulation and the modified analytical embedded-atom method （MAEAM） were used to study the influence of a He atom on the movement of the（a/2）？110？{111} edge dislocation in Ni. First, the calculated Burgers vector distribution shows that the equilibrium dissociation distance （Ded） and the stacking fault energy （Esf） between two partial edge dislocations are about 25.95 ？ and 108 mJ/m2, respectively. Then, the obtained formation energies （Ef） of a He atom at some different sites demonstrate that the He atom is attracted and repelled in the tension and compression regions, respectively. And the He？dislocation interaction reveals that an interstitial He atom plays a more significant role in the dislocation movement than a substitutional He atom. Finally, it is found that the movement of an interstitial He atom is apparent as the first partial dislocation bypasses and the edge dislocation offers fast-diffusion path for the migration of a He atom.展开更多
A modified analytic embedded-atom model(MAEAM) was applied to investigate surface premelting and melting behaviors of Nb(111) plane by molecular dynamics(MD) simulations. First the relaxation of surface interface spac...A modified analytic embedded-atom model(MAEAM) was applied to investigate surface premelting and melting behaviors of Nb(111) plane by molecular dynamics(MD) simulations. First the relaxation of surface interface space at 300 K was studied. Then a number N of the disordered atoms per unit area was determined at the given temperatures to investigate the surface premelting and melting evolution. The obtained results indicated that the premelting phenomena occurred at about 1 100 K and a liquid-like layer emerged on (111) plane simultaneously. As temperature increased up to 2 200 K, the number N grew logarithmically for short-range metallic interactions. Upon 2 350 K surface melting generated originally and the number N increased exponentially with the incremental temperature.展开更多
The modified analytic embedded-atom method and molecular dynamics simulations are applied to the investigation of the surface premelting and melting behaviours of the V（110） plane by calculating the interlayer relax...The modified analytic embedded-atom method and molecular dynamics simulations are applied to the investigation of the surface premelting and melting behaviours of the V（110） plane by calculating the interlayer relaxation, the layer structure factor and atomic snapshots in this paper. The results obtained indicate that the premelting phenomenon occurs on the V（110） surface at about 1800K and then a liquid-like layer, which approximately keeps the same thickness up to 2020K, emerges on it. We discover that the temperature 2020K the V（110） surface starts to melt and is in a completely disordered state at the temperature of 2140K under the melting point for the bulk vanadium.展开更多
基金Project(ZL1405)supported by the Talent Project of Lingnan Normal University,China
文摘The molecular dynamics （MD） simulation and the modified analytical embedded-atom method （MAEAM） were used to study the influence of a He atom on the movement of the（a/2）？110？{111} edge dislocation in Ni. First, the calculated Burgers vector distribution shows that the equilibrium dissociation distance （Ded） and the stacking fault energy （Esf） between two partial edge dislocations are about 25.95 ？ and 108 mJ/m2, respectively. Then, the obtained formation energies （Ef） of a He atom at some different sites demonstrate that the He atom is attracted and repelled in the tension and compression regions, respectively. And the He？dislocation interaction reveals that an interstitial He atom plays a more significant role in the dislocation movement than a substitutional He atom. Finally, it is found that the movement of an interstitial He atom is apparent as the first partial dislocation bypasses and the edge dislocation offers fast-diffusion path for the migration of a He atom.
基金Project(07C445) supported by the Scientific Research Fund of Hunan Provincial Education Department, ChinaProject supported by the Grant of the 11th Fiver-year Plan for Key Construction Academic Subject of Hunan Province, ChinaProject(JJZD0703) supported by the Key Scientific Research Project of Hunan University of Arts and Science, China
文摘A modified analytic embedded-atom model(MAEAM) was applied to investigate surface premelting and melting behaviors of Nb(111) plane by molecular dynamics(MD) simulations. First the relaxation of surface interface space at 300 K was studied. Then a number N of the disordered atoms per unit area was determined at the given temperatures to investigate the surface premelting and melting evolution. The obtained results indicated that the premelting phenomena occurred at about 1 100 K and a liquid-like layer emerged on (111) plane simultaneously. As temperature increased up to 2 200 K, the number N grew logarithmically for short-range metallic interactions. Upon 2 350 K surface melting generated originally and the number N increased exponentially with the incremental temperature.
基金supported by the National Natural Science Foundation of China (Grant No 50671035)the Scientific Research Fund of Hunan Provincial Education Department of China (Grant No 07C445)the Grant of the 11th Five-year Plan for Key Construction Academic Subject of Hunan Province,China
文摘The modified analytic embedded-atom method and molecular dynamics simulations are applied to the investigation of the surface premelting and melting behaviours of the V（110） plane by calculating the interlayer relaxation, the layer structure factor and atomic snapshots in this paper. The results obtained indicate that the premelting phenomenon occurs on the V（110） surface at about 1800K and then a liquid-like layer, which approximately keeps the same thickness up to 2020K, emerges on it. We discover that the temperature 2020K the V（110） surface starts to melt and is in a completely disordered state at the temperature of 2140K under the melting point for the bulk vanadium.
