Molecular Dynamic Simulation Of Tungsten Single Crystal Under Uniaxial Tension

As an important plasma facing material, tungsten is widely used in the nuclear fusion reaction apparatus. In this paper, the influence of temperature and vacancy on the mechanical properties and deformation mechanism of single-crystal tungsten have been studied by means of molecular dynamics simulations.At the temperature of 300K, the stress-strain curve and microscopic deformation structure were analyzed in order to reveal the tensile deformation characteristics and microscopic failure mechanism of the single-crystal tungsten. And the changes of the internal structure of single-crystal tungsten in the process of tension have been analyzed. The results show that the deformation process contains four stages, i.e. elastic deformation, plastic deformation, hardening deformation and failure.In the range of temperature 300K-1000K, the influence of temperature on the mechanical properties and plastic deformation mechanism of single-crystal tungsten has been analyzed. The results show that the temperature increasing, the yield strength decreases significantly.The influence of vacancies on the tensile deformation of the single-crystal tungsten is simulated, in the range of temperature 300K-1000K. The results were compared with those of the complete unit cells. It is discussed for the mechanism of that the single-crystal tungsten with vacancy was more easily to fail.