高强高导铜银合金的结构设计与性能调控

For the applications of high strength and high conductivity Cu-Ag materials on high field pulsed magnet and high precision transmission line, Cu-Ag bulk material with reinforced nanofibers of CuAg alloy and multi-scale Cu layers matrix are designed and prepared by accumulative drawing and bundling(ADB) process. The transformation of interface and substructure induced by nano fibers under large content of plastic deformation will be investigated. The strengthening effect dependence on the nanofibers and multi-scale layers would be analyzed. Electron scattering characteristics of multi-scale layers and alloy phases will be concentrated. The effects of the structure evolution during recrystallization and aging process on strength and conductivity would be focused. The strengthening mechanism and the transport characteristics of nanofibers and multi-scale layers under severe plastic deformation could be elaborated. Precise controlling on mechanical and electrical performance deduced by structure design will be realized. Moreover, high strength and high conductivity CuAg strand with large cross section for pulsed magnet and high conductivity CuAg wire for transmission line could be achieved, which could provide theoretical basis for the research and supply technical support for the material under extreme condition.

针对高场脉冲磁体和高精密电传输线的高强高导CuAg材料需求，采用集束拉拔技术，设计制备以CuAg合金纳米芯丝为增强纤维，多尺寸纯铜层为基体的Cu-Ag体材料。研究大塑性变形纳米纤维化导致的界面和亚结构转变，纳米纤维和多尺寸铜层组态对强化效应的影响，多尺寸铜层与合金相的电子散射特性，再结晶、时效结构变化对强度、电导的影响。阐述极塑变形纳米纤维和多尺寸铜层结构的强化机理、输运特征。实现材料结构设计到力学、电学性能的精确控制。在此基础上，获得脉冲磁体用大横截面高强高导CuAg合金线材和传输线用高导CuAg合金丝材，为新型Cu-Ag合金的研发提供理论依据，为极端条件下的材料应用提供技术支持。

本项目以脉冲磁体用高强高导CuAg材料为研究对象，通过集束拉拔技术获得了以CuAg纳米纤维增强的，以多尺寸铜层为基体的铜银复合线材。系统研究了材料内部宏观网状共晶组织转变为具有椭球状截面的纳米纤维的结构演变特征，明确了铜银界面结构和位错亚结构，揭示了微观结构与材料强化、导电的耦合关系。从拉拔、轧制等加工方式入手，研究了材料变形协调性特点。研究退火处理对纳米纤维结构的影响规律，明确了了纤维粗化和晶粒长大机制。通过高温热压缩行为研究，阐述了材料流变应力特性，拟合了材料本构关系模型，构建了材料热加工图。该研究积累了较多实验理论结果，有效推进了材料的脉冲磁体应用进程。