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 particles 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 nanocrystal (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.