Tip Splitting Dynamics in Degenerate Seaweed Patterns of Aluminum Alloys Induced by Anisotropic Surface Tension
Tip Splitting Dynamics in Degenerate Seaweed Patterns of Aluminum Alloys Induced by Anisotropic Surface Tension
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DOI：
10.1021/acs.cgd.2c01211
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发表时间：
2023-02
期刊：
影响因子：
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通讯作者：
Yumin Wang;Zheng Shi;Shuangming Li;Xin Cao;Bin Yang;Z. Liu;Hui-juan Xing
中科院分区：
文献类型：
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作者：
Yumin Wang;Zheng Shi;Shuangming Li;Xin Cao;Bin Yang;Z. Liu;Hui-juan Xing
研究了Al-4.5wt%Cu、Al-3wt%Mg和商用A356合金在准二维定向凝固过程中退化海藻的形成。通过设计（100）[011]-和（-211）[111]-取向的平面前沿种子，表面张力分布相对于温度梯度方向对称地布置。结果表明，朝向表面张力最大值的生长是优选的，并且尖端倾向于在两个方向上向外生长，导致退化的海藻形成。三种铝合金中退化海藻的比较表明，其形态特征是定性相似的。然而，各向异性的表面张力对退化海藻的生长动力学有显著的影响。这定量地表明，具有较大各向异性的Al合金倾向于表现出具有较小尖端间距（λ）和较高分裂频率（f）的生长。
The formation of degenerate seaweed in Al-4.5 wt % Cu, Al-3 wt % Mg, and commercial A356 alloys during quasi-two-dimensional directional solidification is studied. By designing (100)[011]-and (−211)[111]-oriented planar-front seeds, the surface tension profiles are symmetrically arranged with respect to the temperature gradient direction. The results show that growth toward the surface tension maxima is preferred, and the tips tend to grow outward in both directions, leading to degenerate seaweed formation. The comparison of the degenerate seaweeds in the three Al alloys shows that the morphologic features are qualitatively similar. However, the anisotropic surface tension has a significant effect on the growth dynamics of the degenerate seaweed. This quantitatively indicates that Al alloys with a larger anisotropy tend to exhibit growth with a smaller tip spacing (λ) and a higher splitting frequency (f).