On migration of primary/peritectic interface during interrupted directional solidification of Sn-Ni peritectic alloy.
On migration of primary/peritectic interface during interrupted directional solidification of Sn-Ni peritectic alloy.
复制标题
在SN-NI核能合金的中断定向固化过程中，初级/临界界面的迁移。
DOI：
10.1038/srep24512
复制
发表时间：
2016-04-14
影响因子：
4.6
通讯作者：
Fu H
中科院分区：
文献类型：
--
作者：
Peng P;Li X;Li J;Su Y;Guo J;Fu H
锡镍包晶合金在经历间断定向凝固后，在枝晶组织中观察到初晶/包晶界面在局部等温条件下的迁移。观察到初生Ni3Sn2/包晶Ni3Sn4界面向初生Ni3Sn2相的迁移伴随着位于该界面的液膜的迁移。该界面的迁移速度远快于包晶相变的迁移速度，这主要是由于Tp以下的初生Ni3Sn2相过热，导致该界面上液膜的形核和迁移所致。这种迁移可以归类为液膜迁移(LFM)，水平方向的迁移速度比沿温度梯度方向的迁移速度快得多。分析预测表明，液膜的迁移可分为两个阶段，这取决于Tp以下是否存在初生相。如果等温退火时间不够长，液膜和初生/包晶界面都会向初生相迁移，直到过热的初生相全部溶解。然后，温度梯度区熔化(TGZM)控制了这种向更高温度的迁移过程。
The migration of the primary/peritectic interface in local isothermal condition is observed in dendritic structure of Sn–Ni peritectic alloy after experiencing interrupted directional solidification. It was observed that this migration of primary Ni3Sn2/peritectic Ni3Sn4 interface towards the primary Ni3Sn2 phase was accompanied by migration of liquid film located at this interface. The migration velocity of this interface was confirmed to be much faster than that of peritectic transformation, so this migration was mostly caused by superheating of primary Ni3Sn2 phase below TP, leading to nucleation and migration of liquid film at this interface. This migration can be classified as a kind of liquid film migration (LFM), and the migration velocity at the horizontal direction has been confirmed to be much faster than that along the direction of temperature gradient. Analytical prediction has shown that the migration of liquid film could be divided into two stages depending on whether primary phase exists below TP. If the isothermal annealing time is not long enough, both the liquid film and the primary/peritectic interface migrate towards the primary phase until the superheated primary phase has all been dissolved. Then, this migration process towards higher temperature is controlled by temperature gradient zone melting (TGZM).