强磁场下金属材料凝固过程中的晶体取向研究进展

Study on Crystal Orientation of Metallic Materials During Solidification in High Magnetic Field

近年来,在金属材料凝固过程中施加稳态强磁场受到广泛关注。具有磁晶各向异性的晶体以不同的晶轴平行于磁场时所受的磁化能不同,在诱发的磁力矩作用下其会发生旋转直至磁化能降至最低状态,从而形成择优取向。择优取向的形成通常会引起材料性能的各向异性,进而满足人们对材料特殊性能的需求,因此晶体取向是强磁场材料科学领域的重点研究方向之一。本文介绍了强磁场下晶体发生择优取向的基本原理,并结合共晶型和包晶型合金的凝固特点综述了强磁场下晶体取向方面的研究进展。对于共晶型合金,强磁场下初生相及与含相同初生相的共晶相可能同时形成择优取向。对于包晶型合金,强磁场下初生相与包晶相通常存在特定的取向关系。若二者具有相似的晶体结构与易磁化轴,则取向行为相互促进;若二者的晶体结构与易磁化轴相差较大,则取向过程中存在竞争关系,进而影响各自的取向行为。

In recent years,the application of steady-state high magnetic fields(HMFs)in the solidification process of metallic materials has received extensive attention.When the crystal with magnetic crystal anisotropy is parallel to the magnetic field with different crystal axes,it will undergo different magnetization energies.Under the induced magnetic torque,it will rotate until the magnetization energy drops to the lowest state,thus forming the preferred orientation.The formation of preferred orientation usually leads to the anisotropy of material properties,which can meet the needs of special properties of materials.Therefore,crystal orientation is one of the key research directions in the field of high magnetic field materials science.In this paper,the basic principle of preferred crystal orientation under strong magnetic field is introduced,and the research progress of crystal orientation under strong magnetic field is reviewed in combination with the solidification characteristics of eutectic and peritectic alloys.For eutectic alloys,the primary phase and the eutectic phase with the same primary phase may simultaneously form the preferred orientation under high magnetic field.For peritectic alloys,there is usually a specific orientation relationship between primary phase and peritectic phase under strong magnetic field.If they have similar crystal structure and easy magnetization axis,the orientation behavior will promote each other.If there is a big difference between the crystal structure and the easy axis of magnetization,there will be a competitive relationship in the orientation process,which will affect the orientation behavior of each.