Body-centered Cubic Metals To Reverse The Grain Boundary Atomic-level Simulation

As the iron and steel materials, ceramic materials, semiconductor materials and nano-composite materials and new materials and the deepening of the development of materials is increasing the role of interface. Grain boundary material directly influences the physical, chemical, mechanical and other properties. The characteristics of the grain boundary from the grain boundary are different from the crystal structure and the internal energy. Grain boundary configuration of atoms and energy is to examine the interface-related phenomena such as grain growth, diffusion, impurity segregation, atomic migration, grain boundary sliding, erosion, sedimentation, deformation and fracture behavior of an important foundation. Therefore, the analysis and study the grain boundary energy and grain boundary structure on the material science, metallurgy, solid state physics and solid chemistry provide an important theoretical foundation and guidance. Performance prediction of materials, materials modification and design of new materials and traditional materials has the important guiding significance.In this paper, modified analytical embedded-atom method (MAEAM), combined with heavy-bit lattice (CSL) model, using MATLAB programming from the atomic-scale calculations and analysis of body-centered cubic (BCC) metals Fe (001) face to reverse the grain boundary (GB) of energy and structure of crystals between the translation and expansion of energy and structure of the system, and with the relevant control experiments were observed. Reached the following main conclusions:(1) The computed result had indicated that this kind of staying (001) the surface twist boundary nearby atom site changed, caused the spacing to be small, thus the grain boundary energy became exceptionally high, the crystal boundary structure changed, from this kind of rigid configuration was extremely unstable.(2) To reverse the combination of this rigid grain boundaries (001) grain boundary plane can not be increased with the twist angle is increased, but in the individual (coincidence of the location of the last surface density) value of grain boundary unduly point.(3) When the composition crystal boundary's two parts of crystals are parallel to the crystal boundary appearance to translates, the flaccid energy has not assumed the periodic variation, its cycle and concerns with the minimum repetitive units' length of side. The relative translation may reduce the grain boundary energy. May explain theoretically indirectly in the material the inter granular relative slip distorts mechanism. But this kind of staying (001) twist boundary twist boundary's energy change scope is very small in the translation process.(4) The grain boundary to reverse the expansion can greatly reduce the dislocation so that the relaxation does not reduce the grain boundary, after expansion, the (001) grain boundary, no relaxation to the overall decline in the grain boundary. The crystal boundary place atom has the sufficient activity space in the expansion process to move to the stable position, with the aim of obtaining the lowest grain boundary energy and the stable crystal boundary structure.