Abstract Lamellar eutectic alloys have two main types (floating or locked) of growth patterns depending on the orientations of the two eutectic phases. Recent theoretical studies have suggested that the existence of locked lamellar patterns is linked to that of deep minima in the surface energy plot of the interphase boundaries [Ghosh et al., Phys. Rev. E 91, 022407 (2015)]. We present an experimental study aiming at testing this prediction. We used a near-eutectic In-In2Bi alloy that solidifies into a tetragonal phase e (In-11.5 at % Bi) and a hexagonal phase δ ( In 2 Bi ). Thin samples of this alloy were solidified using a rotating directional solidification stage and analyzed for crystallographic texture by X-ray diffraction. A series of large eutectic grains with low (1 to 3°) mosaic spreads were found to contain either of the following coincidence relationships: A = { 2 1 ¯ 1 ¯ 0 } δ ∥ { 111 } e or E = { 1 1 ¯ 02 } δ ∥ { 111 } e . A-type eutectic grains exhibited a locked type of growth, and E-type eutectic grains a floating type of growth. Given that according to standard crystallographic criteria A-type interphase boundaries have a much smaller surface energy than E-type ones, these findings are in agreement with the theoretical predictions.

中文翻译：

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特殊的相间取向关系和薄 In-In 2 Bi 共晶中的锁定层状生长

摘要 根据两个共晶相的取向，层状共晶合金具有两种主要类型（浮动或锁定）的生长模式。最近的理论研究表明，锁定层状图案的存在与界面边界的表面能图中的深极小值有关 [Ghosh 等人，Phys. 修订版 E 91, 022407 (2015)]。我们提出了一项旨在测试这一预测的实验研究。我们使用了一种近共晶 In-In2Bi 合金，该合金凝固成四方相 e（In-11.5 at % Bi）和六方相 δ（In 2 Bi）。这种合金的薄样品使用旋转定向凝固台进行凝固，并通过 X 射线衍射分析晶体结构。发现一系列具有低（1 到 3°）镶嵌分布的大共晶晶粒包含以下重合关系之一：A = { 2 1 ¯ 1 ¯ 0 } δ ∥ { 111 } e 或 E = { 1 1 ¯ 02 } δ ∥ { 111 } e . A型共晶晶粒呈锁定型生长，E型共晶晶粒呈浮动型生长。鉴于根据标准晶体学标准，A 型界面的表面能比 E 型界面小得多，这些发现与理论预测一致。