Papers by Author: Dmitry V. Sinyaev

Abstract: The paper is devoted to the research of diffusion mechanism in Ni3Al intermetallide over grain boundaries of tilt <111> and <100> by the method of molecular dynamics. It was found that grain boundary diffusion represented the combination of three main mechanisms: migration of atoms along the nuclei of grain boundary dislocations, cyclic mechanism near the nuclei and the formation of the chain of displaced atoms from one nucleus of dislocation to the nucleus of the other one. Diffusion mobility of Ni atoms was essentially bigger than the mobility of Al atoms. Grain boundary slipping and intergrain slipping were also observed during the deformation of the bicrystal.

Abstract: The peculiarities of diffusion process and changes of long and short order parameters at an elastic and plastic deformation of compression and tension near grain boundaries with disorientation axis <111> are studied by the method of molecular dynamics. Whirl displacements of atoms destroying the order near grain boundary superdislocations are noticed at uniaxial deformation of compression. The fracture of superstructural and structural order at uniaxial deformation is accompanied by the deformation of amorphous area. Interdiffusion mechanism is changed in the dependence on deformation, temperature and boundary types.