非晶及纳米晶软磁合金具有高磁导率、低矫顽力和合适的介电常数，是理想的电磁屏蔽材料。当前相关研究鲜有从成分设计角度发展适用于电磁屏蔽的新成分，对粉体微结构和形貌影响电磁屏蔽性能的规律也缺乏系统研究。本项目以高Fe含量的Fe-(B, Si, C)-Cu合金为对象，研究微量过渡金属（Cr，Mo）和少量相似强磁性元素（Co，Ni，Mn）的添加对基础合金非晶形成能力、微结构演化和软磁性能的影响。在优化成分的基础上，结合液态急冷、气雾化和高能球磨工艺并辅以热处理制备非晶、纳米晶粉体，明确制粉和热处理工艺对粉体微结构演化和形貌的影响，评价粉体的电磁屏蔽性能，建立粉体成分、微结构、形貌与电磁屏蔽性能的关联，澄清粉体微结构和形貌影响电磁屏蔽性能的机制，进而实现对其电磁屏蔽性能的调控。发展电磁屏蔽性能优异可控、成本低的Fe基非晶、纳米晶粉体，为非晶及纳米晶电磁屏蔽涂料的实用化提供理论指导和工艺技术支撑。

Soft magnetic amorphous and nanocrystalline alloys are ideal electromagnetic shielding materials due to their high permeability, low coercivity, and proper permittivity. At present, there are few work related to developing new amorphous/ nanocrystalline alloys for electromagnetic shielding from the viewpoint of composition design. The comprehensive research about the effects of the microstructure and morphology of the powders on the electromagnetic shielding properties is also absent. In this proposal, we plan to first study the effects of minor alloying transition metals (Cr or Mo), and a small amount of substitution of similar ferromagnetic elements (Co or Ni) on the amorphous-forming ability, microstructure evolution during crystallization, and soft magnetic properties of Fe-(Si, B, C)-Cu alloys with high Fe content and develop the amorphous alloy compositions suitable for electromagnetic shielding. Subsequently, we prepare amorphous and nanocrystalline powders by combining the melt-spun, gas atomization, ball-milling methods as well as heating treatment to find out the effects of milling and annealing processes on the microstructure and morphology of the powders. We evaluate the electromagnetic shielding properties of the powders, establish the correlation between the composition, microstructure, morphology and the electromagnetic shielding properties to clarify the related mechanism, and achieve the control of the electromagnetic shielding properties of the powders. Finally, we develop new Fe-based amorphous and nanocrystalline powders with excellent and controllable electromagnetic shielding properties and low cost. The proposed study would provide theoretical guidelines and technical supports for the practical applications of the amorphous and nanocrystalline electromagnetic shielding coating materials.