Assignment of Individual Orientations by Gaussian Distribution and Monte-Carlo Grain Growth Simulation by Grain Boundary Character Distribution (GBCD) in Fe-3% Si Alloy

摘要

In order to investigate the effect of GBCD on microstructural evolution, a Monte-Carlo computer simulation method was developed in which the texture of real material was closely reconstructed in the simulated microstructure. This method consists of extracting a volume fraction and a Gaussian half-width from an experimental ODF of a Fe-3 percent Si alloy and planting them into the simulated microstructure. Using the reconstructed microstructure, the recrystallization texture formation characteristic of this alloy was studied with a particular focus on the anisotropic mobility of grain boundaries. By deliberately assigning a high anisotropic mobility (1000 times) to the grain boundaries with a misorientation angle in the range of 20 to 45 degrees, the abnormal grain growth phenomenon was analyzed. It was found that a selective growth of grains occurred when they were subjected to such pertinent conditions as their own high mobility accompanied by the presence of the neighboring low-mobility grains. Grains with a Goss orientation conformed to this general pattern of selective coarsening. Therefore, the present result strongly suggests that the theory of Hayakawa et al. -based on the selective growth of the Goss grains with particular boundary misorientation angles-needs to be modified so as to incorporate more general cases.