Molecular Dynamics Simulation Of The Interaction Between Crack And Dislocation In Silicon

In this paper,molecular dynamics methods are used to study the interaction of cracks and dislocations in silicon,and the influence of dislocations on crack propagation is discussed.Including different temperature bars,different loading rates,the interaction of cracks and dislocations at different relative positions of cracks and dislocations,the fracture toughness of cracks,and a comparative analysis with the results of crack propagation without dislocations,revealing that dislocations and dislocations The microscopic mechanism of crack interaction.Temperature has a greater influence on the crack propagation caused by the interaction of cracks and dislocations.With the increase of temperature,the influence of crack deflection of the dislocation-containing model and the dislocation-free crack is more severe,and the crack deflection of the dislocation-containing model is always greater than Crack deflection in the dislocation-free model.At the same time,temperature also has a greater impact on the fracture toughness of the crack tip,the lower the temperature,the greater the fracture toughness.By calculating the effect of different loading rates on the crack growth caused by the interaction of cracks and dislocations,it is found that the effect of different loading rates on the crack growth state at the same temperature is not obvious.As the loading rate decreases,the fracture toughness of the model decreases in most cases,and the fracture toughness of the dislocation-free model is always higher than that of the dislocation model.The location of the dislocation also affects the crack expansion in silicon.Considering the cases of temperature and dislocation location,the closer the relative location of the crack and dislocation under the same temperature,the greater the effect of dislocation on crack expansion.Considering the loading rate and dislocation location,the lower the loading rate and the more distant the dislocation location,the more obvious the effect on crack deflection.