工业纯铝线晶粒特征与强度及导电率定量关系研究

工业纯铝线是国家电网长距离输电线路上应用的重要导体材料，强度与导电率相互制约是阻碍高强度、高导电率工业纯铝线发展的关键科学问题。前期针对不同变形量工业纯铝线强度与导电率研究发现：强度和导电率存在同步提高现象，进而揭示出晶粒是影响强度与导电率关系的关键因素，通过引入细长晶粒可以有效打破强度与导电率制约关系。然而，如何获得更高强度与导电率的工业纯铝线以及晶粒尺寸与强度、导电率的定量关系仍有待深入研究。本项目拟创新性地结合定向凝固和冷拉拔技术，制备出含有超长细晶工业纯铝线，并对其晶粒尺寸、强度与导电率进行定量表征与测试，揭示拉拔态工业纯铝线晶粒尺寸、强度与导电率的极限值，并通过理论分析和数据拟合，建立晶粒尺寸与强度、导电率的定量关系模型。本项目研究成果有望加深对铝线强度和导电率与晶粒关系的认识，为设计和制备高强度-高导电率铝及铝合金线提供理论指导与实验证据。

Commercially pure Al wire with high strength and high electrical conductivity is the essential conducting materials in the field of long-distance transmission of national power grid. The trade-off relation between strength and electrical conductivity is the bottleneck of the development of commercially pure Al wire. Simultaneous increase in strength and electrical conductivity was observed in the commercially pure Al wire with different area reductions. The grain is the key factor influencing the strength-electrical conductivity relation. Besides, introducing the elongated grains could effectively break the trade-off relation between the strength and the electrical conductivity. However, how to obtain higher strength and electrical conductivity of commercially pure Al wire still needs to be further studied. In addition, the quantitative relation between the grain size and the strength as well as the electrical conductivity has not been established. In this work, the combination of directional solidification and cold drawing technology will be applied to preparing the commercially pure Al wires with ultra-long and fine grains. In addition, their grain size, strength and electrical conductivity would be quantitatively characterized and measured. On the basis of the above results, the limit value of grain size, strength and electrical conductivity of the cold-drawn commercially pure Al wire will be revealed. Furthermore, the quantitative model of the grain size and the strength as well as the electrical conductivity could be established by theoretical analysis and data fitting. The above results of this work are expected to enhance the understanding of the relationship between strength and electrical conductivity and grain size of Al wire, which could also provide the theoretical basis and experimental evidence for the design and preparation of Al and Al alloy wires with high strength and high electrical conductivity.