材料期刊网

Based on the coincidence site lattice model and by use of the molecular dynamics method, the relaxation calculations on the atomic structures of the grain boundaries of various generating functions (SIGMA3, SIGMA5, ..., SIGMA19, ..., SIGMA33) in the transition metal Ni are performed. The features of atomic structures corresponding to the grain boundaries arid the effects of the pre-parameter on the interface structures are given. To study the doping response relating to the properties of materials, the SIGMA3 tilt grain boundary is selected. Based on the interstice and vacancy mechanisms, the interface responses doping boron, nitrogen and phosphorus for the grain boundary are investigated. According to the criterion of the energy in molecular dynamics simulation, the most probable positions of doping impurities and effect of doping impurities on the interface structure are given, and the dependence of the fine structure on doping type and the order of the impurity amount are obtained. The analysis of the local energy for the relaxation region shows that the light impurities, boron, nitrogen arid phosphorus, all have a tendency to segregate on the grain boundary and change the feature of the atomic configuration of the interface to a distinct extent. Then the effects of doping impurities on the interface can be predicted.