Abstract Early grain boundary (GB) decoration was analyzed in a β-metastable titanium alloy by using electron backscatter imaging and diffraction. More than 1000 GBs were analyzed and classified as 'special' or 'general' GBs: A boundary is called 'special' if it is able to form an α GB layer satisfying the Burgers Orientation Relationship (BOR) with both grains within an angular deviation θ 2-BOR ; the others are called 'general' GBs. First, the result gives the probability of a GB to transform early according to a disorientation criterion. 49.5°, 60°/ special HAGBs are clearly identified as preferential GBs for early precipitations whereas 60°/ special HAGBs behave as general GBs. Second, the probability for transformed GBs to respect the double-BOR variant selection (VS) criterion according to θ 2-BOR deviation is evaluated. The probability is close to 100% for GBs with θ 2-BOR up to 10°, random for GBs with θ 2-BOR over 16°, and decreases progressively but remains higher than random with θ 2-BOR in between, i.e. an intermediate domain. In addition the habit plane (HP) VS criterion was considered based only on single trace analysis between HP and GB plane (GBP). In most cases, the HP closeness to the GBP was not a relevant VS criterion.

中文翻译：

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促进β亚稳钛合金β晶界快速和选择性αGB析出的分级标准

摘要 通过电子背散射成像和衍射分析了β-亚稳态钛合金的早期晶界（GB）装饰。对 1000 多个 GB 进行了分析并将其归类为“特殊”或“一般” GB：如果边界能够形成满足伯格斯取向关系 (BOR) 且两个晶粒在角度偏差内的 α GB 层，则该边界称为“特殊” θ 2-BOR ；其他被称为“通用”GB。首先，结果给出了 GB 根据迷失方向提前转换的概率。49.5°、60°/特殊 HAGBs 被明确确定为早期降水的优先 GBs，而 60°/特殊 HAGBs 表现为一般 GBs。第二，根据θ 2-BOR 偏差评估转换后的 GB 遵守双 BOR 变体选择 (VS) 标准的概率。对于 θ 2-BOR 高达 10° 的 GB，概率接近 100%，对于 θ 2-BOR 超过 16°的 GB 是随机的，并且逐渐降低，但仍然高于 θ 2-BOR 介于两者之间的随机，即中间领域。此外，习惯平面 (HP) VS 标准仅基于 HP 和 GB 平面 (GBP) 之间的单迹分析被考虑。在大多数情况下，HP 与 GBP 的接近程度不是相关的 VS 标准。此外，习惯平面 (HP) VS 标准仅基于 HP 和 GB 平面 (GBP) 之间的单迹分析被考虑。在大多数情况下，HP 与 GBP 的接近程度不是相关的 VS 标准。此外，习惯平面 (HP) VS 标准仅基于 HP 和 GB 平面 (GBP) 之间的单迹分析被考虑。在大多数情况下，HP 与 GBP 的接近程度不是相关的 VS 标准。