晶界迁移研究进展及其在TiAl合金中的原位分析

The evolution of grain morphology is accompanied with grain boundary (GB) migration, and the grain morphology significantly determines the properties. Therefore, the key problem in engineering research is to obtain expected microstructures by controlling GB migration. The understanding on GB migration in metals was reviewed and the current study on TiAl alloys was given in this paper. Firstly, the phenomenon and physical model of GB migration were introduced. Then the driving force, especially the diffusion and stress, was analyzed. Secondly, the influence factors of GB migration were discussed, including misorientation, grain boundary triple junctions, curvature, temperature and thermal gradient. Finally, some applications of the regulation of GB migration were introduced. Combined with in-situ observation of the author, the GB migrations of TiAl alloys in single-phase regions at high temperatures were analyzed.