Computational Study Of The Interaction Between Solute Atom And Dislocation In Bcc-Fe

With the advancement of science and technology,the application of metal materials,especially iron-based metal materials in modern industrial fields is becoming more and more extensive.For general metal materials,there is an inverted relationship between toughness and strength and hardness.In order to break through this inversion relationship and explore metal materials with better comprehensive mechanical properties,it is very important to study the mechanical behavior mechanism of metal materials.In order to explore the solid solution strengthening law of bcc-Fe,this paper carried out a computational study of the interaction between solute atoms and the dislocation in bcc-Fe with the aid of first principles and molecular dynamics methods.The results show that:(1)The structure of the solute atoms B,C,N,O at the octahedral interstitial position of bcc-Fe is more stable than the structure of the tetrahedral interstitial position,and when the solute atom migrates from one octahedral gap position to another adjacent octahedral gap position in bcc-Fe,is the tetrahedral gap between the two adjacent octahedral gap positions for the transition;(2)When the solute atoms C,O and bcc-Fe form an interstitial solid solution,the higher the solute atom concentration,the higher the yield point of the structural system,and the less likely the material is to undergo plastic deformation;when the solute atom concentrations are the same,the greater the strain rate,the higher the yield point of the structural system,the less likely the material is to undergo plastic deformation;(3)When the dislocation moves on the slip surface with solute atoms,and the distance between the dislocation and the solute atom is within 5 ?,there will be mutual attraction between the two;the dislocation line moves on the slip plane until it meets the solute atoms,the solute atoms will have a pinning effect on the dislocation line,which will hinder the slippage of the dislocation line,making the structural system less prone to plastic deformation,and increasing the strength and hardness of bcc-Fe.Through this computational study,we have explored the structure and stability of solute atoms in the bcc-Fe matrix,the effect of solute atom type and gap position on the interaction energy of solute atoms and dislocations,and the kinetic process of the interaction between solute atom and dislocation.The results of this study are of great significance to the microscopic theoretical study of the solid solution strengthening law of bcc-Fe and to improve the comprehensive mechanical properties of iron-based metal materials.