Abstract.

We perform the phase-field modeling to investigate the growth pattern selections of the complex dendritic structures in constrained growth with different solidification and orientation conditions. The results show that hexagonal close-packed (hcp) crystals emerge as dendritic and cellular arrays in different planes, originating from the specific hcp anisotropy that allows different growth preferences between the basal and cylindrical planes. A morphological transition of the titled dendrites to tip-splitting dendrites arises reflecting the competition between the preferred orientation induced primary growth and the misorientation induced sidebranching formation. Furthermore, the dendritic patterns exhibit sharper tips and the more significant sidebranches, while the cellular pattern is changed from the symmetric cells to the tip-splitting cells, and to seaweeds with the increase of anisotropy strength, indicating the competitive mechanism of the in-plane anisotropy induced growth promotion and the out-plane anisotropy induced growth restriction. We expect to understand the growth competition, the morphology selection, as well as the orientation dependence of the complex dendritic structures in the three-dimensional (3D) constrained growth.

Graphical abstract

中文翻译：

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六方密堆积晶体受约束生长中复杂树枝状结构的相场建模。

摘要。

我们执行相场建模，以研究在不同凝固和取向条件下约束生长中复杂树突结构的生长模式选择。结果表明，六方密堆积（hcp）晶体在不同平面中以树突状和细胞阵列形式出现，源于特定的hcp各向异性，该各向异性允许基面和圆柱面之间具有不同的生长偏好。标题树突向尖端分解树突的形态转变出现，反映了优选取向诱导的初生生长和取向错误诱导的侧枝形成之间的竞争。此外，树突状模式显示出更尖的尖端和更显着的侧枝，而细胞模式则从对称细胞变为尖端分裂细胞，随着各向异性强度的增加，对海藻的生长也产生了影响，表明了平面内各向异性诱导生长促进和平面外各向异性诱导生长受限的竞争机制。我们希望了解生长竞争，形态选择以及三维（3D）约束生长中复杂树突结构的取向依赖性。

图形概要