水平铸轧难混溶Cu-Fe合金组织调控与电磁屏蔽性能研究

高Fe含量的亚稳难混溶Cu-Fe合金是一种性能优越的新型铜合金，兼具优良的电导率和磁性能，在宽频段内均有良好的电磁波屏蔽性能，应用前景广泛。然而我国高Fe含量Cu-Fe合金制备技术和产业应用远落后国际先进水平，高品质产品基本依赖于进口，其主要瓶颈是制备过程中易形成严重成分偏析以及富铁相尺寸粗大，对此缺乏相应的控制手段。鉴于此，本项目采用水平连续铸轧技术制备该合金，分析制备工艺参数对合金凝固行为及组织的影响规律和机制，明确抑制亚稳液相分离形成的工艺窗口，揭示制备过程中多物理场耦合作用下液-液相分离与液-固转变的竞争机制，明晰亚稳液相分离抑制的技术工艺及机制，阐明此过程中富铁相发达树枝晶与胞状枝晶的竞争生长行为及转变机制，构建铸轧亚快速非平衡凝固过程中富铁相生长动力学模型，揭示制备组织与性能的内在关联性。本项目的顺利实施对于我国高品质Cu-Fe合金制备具有积极的科学意义。

Metastable immiscible Cu-Fe alloy with high Fe content is a new type of copper alloy with excellent properties. It has high electrical conductivity and magnetic properties, and thus shows good electromagnetic shielding effectiveness in wide frequency range, which has a widespread application prospect. However, the preparation technology and industrial application of Cu-Fe alloy in our country are far behind the international advanced level, and the high-quality advanced alloy depends heavily on imports. The critical problems are that the formation of serious composition segregation and coarsening of Fe-rich phase, and the corresponding control methods are still lacking up to now. Hence, horizontal continuous twin-rolling casting technology is adopted in this project to fabricate the high-quality alloy. The influence of processing parameters on the prepared microstructure is analyzed and uncovered, and process window for suppressing formation of metastable liquid phase separation is also explored. Additionally, competitive mechanism of liquid-liquid phase separation and liquid-solid transformation under the coupling effect of multiple physical fields in the preparation process is revealed, and the preparation technology and mechanism for suppressing formation of metastable liquid phase separation are clarified. The competitive growth behavior and corresponding transition mechanism between the developed dendrite and cellular dendrite of Fe-rich phase are also investigated. Based on synergy of Thermodynamics and Kinetics, the non-equilibrium dendrite growth model of Fe-rich phase during the sub-rapid solidification process is established. And the correlation between the prepared microstructure and resultant properties is investigated. The successful implementation of the project has an important scientific significance for the preparation of high-quality Cu-Fe alloy in China.