The deformation mechanism responsible for the high-cycle rotating bending fatigue of a high-Nb TiAl alloy was investigated. Fatigue deformation in the γ phase was dominated by superlattice dislocations [0 1 $\overline{\text{1}}$] and twinning. Dislocations 〈1 1 0〉 in the B2 phase can be induced by twins in the adjacent γ phase, which has a low stacking fault energy owing to the high Nb content. Stress transfer between two adjacent phases can be accomplished through atomic rearrangement of the interface by twinning. The local stresses were accommodated by the continuous dislocation slip of the B2 phase, deformation twins, and twin intersections in the γ phase.

中文翻译：

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高 Nb TiAl 合金在高周疲劳过程中的孪生诱导位错和协调变形行为

研究了导致高 Nb TiAl 合金高周旋转弯曲疲劳的变形机制。γ 相的疲劳变形以超晶格位错为主 [0 1$\overline{\text{1个}}$] 和结对。B2 相中的位错 <1  1 0> 可由相邻 γ 相中的孪晶引起，由于高 Nb 含量，其具有低堆垛层错能。 两个相邻相之间的应力转移可以通过孪晶对界面进行原子重排来实现。局部应力由 B2 相的连续位错滑移、变形孪晶和 γ 相中的孪晶相交所吸收。