Abstract This work identifies the mechanisms governing dislocation transmission across lamellar interfaces in a Ti-45Al-2Nb-2Mn (at.%) + 0.8(vol%) TiB2 (Ti4522XD) alloy. With this aim, a microgrip and a microtensile specimen were designed and fabricated using a focused ion beam (FIB), to test micrometer-sized specimens in tension. The deformation mechanisms acting in a microtensile specimen of a Ti4522XD alloy were investigated through electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). The results revealed that domain boundaries (order variant) and lamellar interfaces (order variant, true twin and pseudo-twin) are relatively transparent to dislocation propagation, but they present significant differences in the geometrical alignment between the incoming and outgoing slip systems. While for order variant interfaces, the incoming and outgoing slip systems are perfectly aligned, true twin and pseudo twin interfaces require a change in slip plane and direction, which leaves residual dislocations with Burgers vectors lying on the interface plane. The analysis of the slip transfer mechanisms revealed that the outgoing slip system is governed more by the maximum geometrical alignment, than the applied resolved shear stress.

中文翻译：

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γ-TiAl 薄片在张力下的滑移传递

摘要 这项工作确定了控制 Ti-45Al-2Nb-2Mn (at.%) + 0.8(vol%) TiB2 (Ti4522XD) 合金中跨层状界面位错传输的机制。为此，使用聚焦离子束 (FIB) 设计和制造了一个微型夹具和一个微拉伸试样，以测试微米级试样的张力。通过电子背散射衍射 (EBSD) 和透射电子显微镜 (TEM) 研究了 Ti4522XD 合金微拉伸试样的变形机制。结果表明，域边界（顺序变体）和层状界面（顺序变体、真孪晶和伪孪晶）对位错传播相对透明，但它们在传入和传出滑动系统之间的几何对齐方面存在显着差异。而对于订单变体接口，传入和传出滑移系统完全对齐，真孪晶和伪孪晶界面需要改变滑移平面和方向，这会在界面平面上留下带有 Burgers 矢量的残余位错。滑移传递机制的分析表明，输出滑移系统更多地受最大几何排列的控制，而不是施加的解析剪切应力。