Molecular Dynamics Simulation Of Effect Of Tilt Angle On Mechanical Properties Of Magnesium Bicrystals

As an kind of new materials that having great potential in21centry, Nano-materials has drawn enormous attentions from the globe due to its unique properties in mechanics, electrics, magnetics, chemist etc fields. Recently, the studies of nano-materials has been developing prosperously, together with the fast growing developing speed ot nano-science. So far, there are two main methods to study nano-materials:the first one is by doing experiments using traditional lab method; the other one is to use Molecular Dynamic simulations(MD simulation).As a new method of studying nano-materials, MD simulation has been used by a lot of researchers. By using high-performance computers, researchers could conduct series of experiments of qualitative studies, and the micro-structures during transformation inside the materials. This brings a lot convenience to the study of atomic movement, dislocation movement and other mechanism.Polycrystals, as a very important structure of nano-materials, has been studied by many researchers. Compared with monocrystal, polycrystals has amount of Grain Boundaries(GB) in structure.And the grain boundaries could have great impact on the mechanical properties of the materials, such as:Young’s Modulus, yield stress, flow stress and so on. So in order to reveal the impact of tilt angles on the mechanism of polycrystals, we conducted this project.The effects of grain boundary on the deformation behavior of magnesium bicrystals under tensile loading are investigated using molecular dynamics simulation method. Deformation mechanism of both asymmetric and symmetric magnesium bicrystals are studied. The results mainly concluded:(1)The result shows that the twist angle could exert a significant impact on the flow stress in the plastic stage.(2) It is found that the plastic property of symmetric magnesium bicrystals is muchbetter, compared with asymmetric counterpart.(3)In addition, for bicrystalline metals with large twist angles, the plastic response isbetter than those of small angles, due to the dislocation nucleation activities in thegrain boundary region.