Abnormal Grain Growth Induced by Boundary Segregation of Solute Atoms
Abnormal grain growth (AGG) proceeds in case that normal grain growth is inhibited. It has long been known that the inhibition involves finely dispersed particles and/or the development of specific textures. There is another strong obstacle against the grain boundary (GB) motion; the solute atoms can reduce their energy by moving from the bulk into a GB. Resultant interaction between the solute atoms and a GB makes the GB motion more difficult. However the role of the GB segregation effect on AGG has not been clarified. In this study we simulate the 2D and 3D grain growth accompanying boundary segregation of solute atoms by using a phase-field model. It is shown that the segregation plays an important role on the occurrence of AGG. The boundary-segregation-induced AGG can take place when the average driving force of grain growth approaches a critical condition for pinning-depinning transition in solute-drag atmosphere.
S.-J.L. Kang, M.Y. Huh, N.M. Hwang, H. Homma, K. Ushioda and Y. Ikuhara
S. G. Kim et al., "Abnormal Grain Growth Induced by Boundary Segregation of Solute Atoms", Materials Science Forum, Vols. 558-559, pp. 1093-1099, 2007