Reexaminations of the effects of magnetic field on the nucleation of undercooled Cu melt

Abstract

The effect of a high static magnetic field on the nucleation of an undercooled Cu melt has been investigated using a glass slag fluxing technique in a 12 T superconductor magnet. Controlled heating cycles with and without a magnetic field are performed and the results indicate that the magnetic field has no single effect on the mean undercooling of undercooled Cu liquid, which is different from previous reports. The high static magnetic field can enhance the undercooling of Cu at first, and the effect is weakened with increasing number of heating cycles. The undercooling of undercooled Cu is saturated at around 250 K regardless of the magnetic field after a certain number of heating cycles. The effects are interpreted on the basis of the thermodynamic and magnetohydrodynamic effects of the magnetic field on the undercooled melt and the heterogeneous nucleation theory.

Reduced Wettability of Solids by a Liquid Ga–In–Sn Alloy in a Steady Magnetic Field

“…In recent decades, steady magnetic fields (SMFs) have been widely applied in metallic materials processing, e.g., electromagnetic continuous casting, semiconductor crystal growth, crystal orientation, magnetic separation, and solidification processing, owing to their contactless interactions and different magnetic effects. , It has been found that an SMF can exert an influence on nucleation, − the solid/liquid interface morphology, , melt undercooling, , etc. These phenomena imply that the SMF apparently modifies the interfacial properties.…”

Solidification Processing of Metallic Materials in Static Magnetic Field: A Review

“…This leads to an increase in the transferring time of the atom to nucleus, which, in turn, enhances the undercooling. Wang et al systematically investigated the effect of the SMF on the degree of undercooling [32,33]. It was found that the undercooling for homogeneous nucleation is irrelevant to the SMF intensity, but influenced undercooling for heterogeneous nucleation, as shown in Figure 4.…”

Effect of steady magnetic field on undercooling of Al-Cu alloy melts

“…In recent decades, the steady magnetic field (SMF) has been widely applied to materials processing and it is frequently used to modify the microstructures and properties. For solidification processing, the SMF has been found to change the degree of undercooling of metal melts such as pure Cu [7,8], pure Al [9], pure Sn and pure Zn [10], and of alloy melts such as Ni-Cu [11] and Al-Cu [12,13]. Further, the researchers proposed various possible explanations to clarify the nature of the change in undercooling in an SMF, such as the delayed formation of the nucleationcatalyzed oxides [11] and the increase in solid/liquid interfacial tension due to the magnetic dipolar interaction [13].…”