Compared with the growing applications of peritectic alloys, none research on the fluid permeability K of dendritic network during peritectic solidification has been reported before. The fluid permeability K of dendritic network in the mushy zone during directional solidification of Sn-Ni peritectic alloy was investigated in this study. Examination on the experimental results demonstrates that both the temperature gradient zone melting (TGZM) and Gibbs-Thomson (G–T) effects have obvious influences on the morphology of dendritic network during directional solidification. This is realized through different stages of liquid diffusion within dendritic mushy zone by these effects during directional solidification. The TGZM effect is demonstrated to play a more important role as compared with the G–T effect during directional solidification. Besides, it is shown that the evolution of dendrite network is more complex during peritectic solidification due to the involvement of the peritectic phase. Through the specific surface S_V, analytical expression based on the Carman–Kozeny model was proposed to analyze the fluid permeability of dendritic mushy zone in directionally solidified peritectic alloys. In addition, it is interesting to find a rise in permeability K after peritectic reaction in both theoretical predication and experimental results, which is different from that in other alloys. The theoretical predictions show that this rise in fluid permeability K after peritectic reaction is caused by the remelting/resolidification process on dendritic structure by the TGZM and G–T effects during peritectic solidification.

与包晶合金的日益增长的应用相比，以前尚无关于包晶凝固过程中枝晶网络的流体渗透率K的研究。流体渗透率K研究了Sn-Ni包晶合金定向凝固过程中糊状区枝状网络的变化。对实验结果的检验表明，温度梯度区熔化（TGZM）和吉布斯-汤姆森（G–T）效应均对定向凝固过程中的树枝状网络形态有明显影响。通过定向凝固过程中的这些作用，可以通过树枝状糊状区域内液体扩散的不同阶段来实现。与定向凝固过程中的G-T效应相比，TGZM效应起着更重要的作用。此外，由于包晶相的参与，表明在包晶凝固过程中枝晶网络的演化更加复杂。通过比表面S_V提出了基于Carman-Kozeny模型的解析表达式，以分析定向凝固包晶合金中树枝状糊状区的流体渗透性。此外，有趣的是在理论预测和实验结果中都发现了包晶反应后磁导率K的增加，这与其他合金的情况不同。理论预测表明，包晶反应后流体渗透率K的升高是由包晶凝固过程中TGZM和G-T效应对树枝状结构的重熔/再凝固过程引起的。