共晶高熵合金是一种兼具高强度和强塑性的合金，其性能取决于凝固组织。而强磁场作为一种极端外物理 场， 其对金属凝固过程的调控作用已得到广泛证实。 因此， 开展强磁场下金属凝固理论研究具有深远意义。 以 AlCoCrFeNi2.1 共晶高熵合金为对象，研究了强磁场对其定向凝固后的组织演变和力学性能的影响。结果表明，强磁场下 定向凝固的共晶高熵合金组织为FCC初生相包含FCC/BCC共晶片层，强磁场通过提高固液界面稳定性，细化共晶片 层间距和改变初生相择优取向实现了合金硬度、拉伸性能的提升。 磁场处理后，合金最大伸长率达到33%时，极限抗拉 强度高达985MPa，因此强磁场可作为合金铸造过程中获得强度和韧性耦合的有效调控手段。

 Eutectic high-entropy alloys exhibit high strength and excellent ductility, and their properties are determined by their microstructure. Magnetic fields, as extreme external physical fields, have been widely proven to significantly affect the solidification process of alloys. Therefore, research on the theory of metallic solidification under a high magnetic field is highly important. The effect of a magnetic field on the directional solidified AlCoCrFeNi2.1 eutectic high-entropy alloy under different drawing speeds was studied. The microstructures of the AlCoCrFeNi2.1 eutectic high-entropy alloy under magnetic field-assisted directional solidification include primary phase dendrites (FCC phase) and eutectic lamellar phases (FCC/BCC phase). The strong magnetic field improves the hardness and tensile properties by enhancing the stability of the solid-liquid interface, refining the spacing of the eutectic lamellar layers and changing the preferred orientation of the primary phase. Under a high magnetic field, the elongation of the AlCoCrFeNi2.1 eutectic high-entropy alloy reaches approximately 33%, with an ultimate tensile strength of 985 MPa. Therefore, a strong magnetic field can be used as an effective way to obtain the coupling of strength and toughness during the casting process.