Migration of liquid particle from mushy zone interface in temperature gradient

摘要

The thermal stabilization process after which directional growth of crystals initiates is crucial in obtaining the initial growth conditions of directional solidification. A mushy zone is formed during thermal stabilization due to the imposed temperature gradient. The difference in melt concentrations across the liquid particles in the mushy zone induces simultaneous remelting/resolidification by the temperature gradient zone melting (TGZM), and this phenomenon is called the migration of liquid particle. It is usually assumed that the migration of liquid particle initiates from the superheated solid phases in the mushy zone in single phase alloy. However, the migration of liquid particles from the mushy zone interface at peritectic temperature T-p during thermal stabilization has been confirmed in a Sn-Ni peritectic alloy (Liquid + Ni3Sn2 -> Ni3Sn4) in this work. This newly observed migration of the liquid particles from the mushy zone interface has been described to simultaneous remelting/resolidification at the leading/trailing interface of the liquid particles through a diffusion-controlled analytical model. (C) 2019 Elsevier Ltd. All rights reserved.