Clarification and Functionalization of Micro -and Mezzo structure near Boundary between Different Phase in Single-crystalline Super Metals

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In order to obtain the high performance material through the control of the microstructure of the materials the computational strategies to relate the microstructure and its evolution due to macroscopic deformation has been generalized to adopt the present problems. Subsequently, the methods have been applied to the problems associated with the evaluation of the macroscopic characteristic feature of the material with microstructures. The followings are the main results.(1) Subdivisions Method employing the eigen strain fields has been modified to obtain an accurate solution and the method has been used to evaluate the overall properties of short fiber reinforced composites and clarified the proper arrangement of reinforcement to realize the desired characteristic feature of the composite.(2) With a computational model employing the strain gradient constitutive equation for plastic deformation of the matrix material and a homogenization method, the effects of the volume fraction, size and distribution pattern of reinforced particles and direction of particle distribution with respect to applied stress on the macroscopic characteristic feature of the composites were clarified. The main mechanism of the increase of the deformation resistance in the plastic range is the high strain gradient in the matrix material, which increases with decreasing distance between the particles. These all suggest the way of an enhancement of resistance of the deformation behavior.(3) A three dimensional homogenization method employing the constitutive equation based on the crystal plasticity theory has been developed and the effect of the volume fraction of γ´ phase and the difference of crystalline directions of γ'/γ phases on the characteristic feature of the alloy. It is significantly affected by the strain distribution due to the inhomogeneous deformation induced by the γ´ phase precipitation on a microscopic scale