The Simulation Study Of Effect Of Hydrogen On Mechanical Properties Of ?-Fe

Computer simulation can not only make better understanding of interior character and macroscopic mechanical properties by simulation of various experiment process,but also predict the properties of materials before the preparation of new materials.Molecular dynamics simulation provides theoretical guidance for the design of new structural materials with excellent performance.Molecular dynamics simulation is an important method of computer simulation.In this paper,<100>?-Fe nanowire and ?-Fe nano-plate with void are selected as study objects.The effect of hydrogen atoms on the mechanical properties of ? iron under tensile loading is studied by molecular dynamics simulation.The microstructure evolution of ?-Fe during tensile process is analyzed by visualization software(Ovito).The main research content and results are as follows:(1)The effect of hydrogen on the mechanical behavior of <100>?-Fe nanowires with different cross section sizes is studied.The results indicate that hydrogen atoms decrease the peak stress of <100>?-Fe nanowires and increase the average flow stress at 300 K.The difference of peak stress of samples with and without hydrogen increases with the increase of cross section size at 300 K.The nucleation and growth of twin is the main deformation mechanism.Hydrogen atoms do not change the plastic deformation mechanism of iron nanowires.(2)The effect of temperature and strain rate on the mechanical properties of ?-Fe nanowire is also studied.It indicates that the peak stress of Fe nanowires decreases with the increase of temperature.The strain rate has little effect on the peak stress of <100>?-Fe nanowires.(3)The effect of hydrogen on the mechanical properties of ?-Fe nano-plate with void is studied.The results indicate that the peak stress of nano-plate decreases with the increase of void size.The peak stress of ?-Fe nano-plate decreases with the increase of hydrogen concentration.The average flow stress increases with the increase of hydrogen concentration,and decreases with the increase of temperature.The nucleation and growth of twin is the main deformation mechanism,and the twins nucleate from the void.