Modeling And Simulation Of Microscopic Mechanics Of Particle Strengthening Based On Dislocation Dynamics

The critical resolved shear stress?CRSS?is the minimum shear stress to start the movement of the slip system for metallic materials,its value to some extent determines the ability to resist the plastic deformation of materials.Due to the difficulties of the preparation of materials and the limits of measurement methods,getting the value of CRSS with experimental methods can be challenging.In these twenty years,dislocation dynamics is regarded as a preferable method to predict it.CRSS of materials,which strengthen by particles and are popular at present,is related to not only dislocation density and the interaction between dislocation and solid solution atoms,but also the distribution of particles and the interaction between dislocation and particles.So it's important to built a corresponding model,which can describe the mechanical behavior quantifiably according to the real crystal structure and the state of dislocation of material with dislocation dynamics,and predict CRSS.In this paper,with the method of two-dimension discrete dislocation dynamic?2DDD?,taken the Ni-base alloy with L1₂ long-range ordered?'precipitates as an example,the effects of the volume fraction and mean radius of particles,antiphase boundary?APB?energy and the form of dislocation on the strengthening of metals and alloys were investigated.This paper considered the LSW distribution rule of particles to make the model can be close to the distribution of particles in real Ostwald ripened crystal.The simulation was came true by hybrid programming with Matlab and C language.A proper incremental step was choosed by the displacement of nodes,which increased the computing speed and ensured the computational accuracy.According to the result of simulation,when the volume fraction and mean radius of?'precipitate are in low level,CRSS of Ni-base alloy would increase with the rise of the volume fraction and mean radius of?'precipitate and APB energy.With the same value of parameter,CRSS of Ni-base alloy with edge dislocation is higher than with screw dislocation,and the difference increased with the increase of the volume fraction of?'precipitate.