Simulation of the effect of strengthening-phase particles on the plastic deformation of a two-dimensional polycrystal

Abstract

The method of molecular dynamics was used to investigate the effect of strengthening phase par ticles on the process of plastic deformation in two dimensional nanocrystalline material at given temperature, hydrostatic pressure, and the maximum shear stress. We consider the deformation of a single phase nanoc rystal (material 1); a nanocrystal with particles located at grain boundaries and triple junctions and having atoms whose size is 10% larger than that of the matrix atoms (material 2), 10% less than the size of the matrix atoms (material 3), and is equal to it (material 4). The rate of creep for materials 1 and 2 was approximately the same, but the deformation mechanisms were different. The lowest creep rate was obtained for material 4. It has been shown that in the presence of second phase inclusions, despite the small grain size, a significant contribution to the material deformation comes from the motion of dislocations, especially in the case of material 2 with incoherent particles. The understanding of the deformation processes developed using model polycrystals can be used for elucidating the precipitation hardening mechanisms of alloys and the structure evolution of such materials during plastic deformation.

Two-dimensional model of the ordered alloy for the investigation of martensitic transformations

“…However, in the present study for the investigation of two-dimensional crystal it is worthwhile to use simple pair potential among which the potentials of Born-Mayer, Lennard-Jones, Morse, to name a few. For example, Lennard-Jones pair potential was successfully used for investigation of effect of ultrasound and annealing on the structure of nanocrystalline material [11] and studying of plastic deformation [12][13][14][15][16][17]. Lennard-Jones function is a two parametric potential which allows one to reproduce the experimental data, for example, for interatomic potential and bonding energy, however, the rigidity of the bond will in its turn dependent on these parameters.…”

Effect of small perturbations on the evolution of polycrystalline structure during plastic deformation

“…This paper considers the two dimensional model of a polycrystal with nanoscale grains in order to obtain preliminary qualitative results. This two dimensional model has successfully been applied previously to study various aspects of plastic deformation [20][21][22][23][24][25].…”

Two-Dimensional Molecular Dynamics Simulation for Studying of Grain Refinement

“…Model based on dislocation density was developed to investigate the evolutions of dislocation density, cell size and flow stress during plastic deformation [11]. Two-dimensional (2D) molecular dynamics approach was used for the investigation of grain boundary sliding (GBS) under SPD [12][13][14][15]. To investigate realistic cases one should carry out 3D simulation, but although 2D simulation models are strong simplifications of the real systems, they can provide results of physical relevance [12][13][14][15][16][17].…”