Based on the embedded atom method (EAM) proposed by Daw and Baskes and Johnson's model, this paper constructs a new N-body potential for bcc crystal Mo. The procedure of constructing the new N-body potential can b...Based on the embedded atom method (EAM) proposed by Daw and Baskes and Johnson's model, this paper constructs a new N-body potential for bcc crystal Mo. The procedure of constructing the new N-body potential can be applied to other metals. The dislocation emission from a crack tip has been simulated successfully using molecular dynamics method, the result is in good agreement with the elastic solution.展开更多
An analytic method is proposed to calculate the formation enthalpy directly from empirical n-body potential and applied to the binary and ternary systems consisting of the refractory metals Mo, Nb, Ta and W. It turns ...An analytic method is proposed to calculate the formation enthalpy directly from empirical n-body potential and applied to the binary and ternary systems consisting of the refractory metals Mo, Nb, Ta and W. It turns out that the calculated enthalpies are in overall agreement with experimental observations and some other theoretical calculations. Interestingly, it shows that the formation enthalpies of the ternary systems are significantly affected by those of the constituent binary systems.展开更多
The microprocesses of deformation and fracture of Bi-segregated copper bicrystals Σ33 (545) 58.99°, Σ11 (323) 50.48° and Σ9 (212) 38.94° have been simulated by molecular dynamics in order to study th...The microprocesses of deformation and fracture of Bi-segregated copper bicrystals Σ33 (545) 58.99°, Σ11 (323) 50.48° and Σ9 (212) 38.94° have been simulated by molecular dynamics in order to study the relationship between the grain boundary embrittlement (GBE) and grain boundary (GB) structure. It is shown that GBE is related to the segregated concentration and distribution of Bi atoms, while Bi segregation is re- lated to the GB structure. Due to their different structures, the bicrystals Σ33, Σ11 and Σ9 show an increasing propensity for Bi segregated concentration. So under the action of external force, Σ33, Σ11 and Σ9 show transgranular ductile, intergranular tearing and intergranular brittle fracture modes, respectively.展开更多
The segregation of bismuth atoms on the [101] tilt copper grain boundaries Σ3 (111) 70.53°, Σ33 (545) 58.99°, Σ11(323) 50.48° and Σ9 (212) 38.94° has been studied by pseudo-molecular dynamics u...The segregation of bismuth atoms on the [101] tilt copper grain boundaries Σ3 (111) 70.53°, Σ33 (545) 58.99°, Σ11(323) 50.48° and Σ9 (212) 38.94° has been studied by pseudo-molecular dynamics using the empirical N-body potentials. The relationship between bismuth segregation and grain boundary structure has been discussed in detail.展开更多
基金The project supported by the National Natural Science Foundation of China
文摘Based on the embedded atom method (EAM) proposed by Daw and Baskes and Johnson's model, this paper constructs a new N-body potential for bcc crystal Mo. The procedure of constructing the new N-body potential can be applied to other metals. The dislocation emission from a crack tip has been simulated successfully using molecular dynamics method, the result is in good agreement with the elastic solution.
基金support from the National Natural Science Foundation of China (Grant Nos. 50531040 and 50871058)the Ministry of Science and Technology of China (Grant No. 2006CB605201), and the Administration of Tsinghua University
文摘An analytic method is proposed to calculate the formation enthalpy directly from empirical n-body potential and applied to the binary and ternary systems consisting of the refractory metals Mo, Nb, Ta and W. It turns out that the calculated enthalpies are in overall agreement with experimental observations and some other theoretical calculations. Interestingly, it shows that the formation enthalpies of the ternary systems are significantly affected by those of the constituent binary systems.
基金The subject supported by the Chinese Academy of Sciences and National Natural Science Foundation of China
文摘The microprocesses of deformation and fracture of Bi-segregated copper bicrystals Σ33 (545) 58.99°, Σ11 (323) 50.48° and Σ9 (212) 38.94° have been simulated by molecular dynamics in order to study the relationship between the grain boundary embrittlement (GBE) and grain boundary (GB) structure. It is shown that GBE is related to the segregated concentration and distribution of Bi atoms, while Bi segregation is re- lated to the GB structure. Due to their different structures, the bicrystals Σ33, Σ11 and Σ9 show an increasing propensity for Bi segregated concentration. So under the action of external force, Σ33, Σ11 and Σ9 show transgranular ductile, intergranular tearing and intergranular brittle fracture modes, respectively.
基金The subject supported by the Chinese Academy of Sciences and National Natural Science Foundation of China
文摘The segregation of bismuth atoms on the [101] tilt copper grain boundaries Σ3 (111) 70.53°, Σ33 (545) 58.99°, Σ11(323) 50.48° and Σ9 (212) 38.94° has been studied by pseudo-molecular dynamics using the empirical N-body potentials. The relationship between bismuth segregation and grain boundary structure has been discussed in detail.
