Abstract The precipitation orientation of α phases in a Ti-55511 alloy during the heat treatment and the subsequent hot deformation is investigated. It is observed that the β grains prominently influence the precipitation process of α phases, i.e., for the neighbouring β grains without similar {110} pole, the precipitation orientation of grain boundary (GB) α phases (αGB) keep {0001}//{110}β1 or {0001}//{110}β2 to maintain the burgers orientation relationship (BOR) with the neighbouring β grains. For the neighbouring β grains with similar {110} pole, the {0001} poles of αGB phases precipitate parallel to this similar {110} pole and maintain BOR with the neighbouring β grains. For the neighbouring β grains with multiple similar {110} poles, the {0001} poles of αGB phases precipitate along these similar poles and maintain BOR with the neighbouring β grains. Besides, the interface instability nucleation and sympathetic nucleation are the main nucleation modes of the GB widmanstatten α phase (αWGB), which primarily precipitate within β grains with the similar orientation of αGB phases. The intracrystalline widmanstatten phase (αWI) precipitate in a single β grain with 12 precipitation orientations. The BOR between αWI phases and β grains is destroyed during the subsequent hot compressive deformation.

中文翻译：

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Ti-55511钛合金热处理及后续热变形过程中α相的析出行为及取向演化机制

摘要 研究了Ti-55511合金在热处理和随后的热变形过程中α相的析出取向。观察到β晶粒显着影响α相的析出过程，即对于没有相似{110}极的相邻β晶粒，晶界（GB）α相（αGB）的析出取向保持{0001}// {110}β1 或 {0001}//{110}β2 以保持与相邻 β 晶粒的汉堡取向关系 (BOR)。对于具有相似 {110} 极的相邻 β 晶粒，αGB 相的 {0001} 极平行于该相似的 {110} 极沉淀并与相邻 β 晶粒保持 BOR。对于具有多个相似{110}极的相邻β晶粒，αGB 相的 {0001} 极沿这些相似的极点沉淀并与相邻的 β 晶粒保持 BOR。此外，界面不稳定成核和交感神经成核是GB widmanstatten α相（αWGB）的主要成核方式，主要在β晶粒内析出，具有相似的αGB相取向。晶内 widmanstatten 相 (αWI) 以具有 12 个沉淀方向的单个 β 晶粒沉淀。在随后的热压缩变形过程中，αWI 相和 β 晶粒之间的 BOR 被破坏。晶内 widmanstatten 相 (αWI) 以具有 12 个沉淀方向的单个 β 晶粒沉淀。在随后的热压缩变形过程中，αWI 相和 β 晶粒之间的 BOR 被破坏。晶内 widmanstatten 相 (αWI) 以具有 12 个沉淀方向的单个 β 晶粒沉淀。在随后的热压缩变形过程中，αWI 相和 β 晶粒之间的 BOR 被破坏。