尺寸变化对Cu-Nb-Cu多芯复合线材微观结构及性能影响

Effect of Size Change on the Microstructure and Properties of Cu-Nb-Cu Multicore Composite Wires

采用集束拉拔技术制备出高强高导Nb管增强Cu-Nb多芯复合线材,样品直径为Φ2.5 mm时,强度接近1.1 GPa,导电率达到74%IACS。选取不同尺寸线径(Φ3.0 mm、Φ2.7 mm、Φ2.5 mm)的复合线材,通过场发射扫描电镜测试手段表征了不同尺寸线材的芯丝形貌、Cu-Nb界面的微观结构,探讨了多尺寸条件下芯丝和界面微观组织的演变规律及特性,最后结合σ-ε曲线图和R-T曲线图,详细分析了尺寸变化所引起线材性能的演变机理。

The Cu-Nb multicore composite wires reinforced by high-strength and high-conductivity Nb tube were prepared by a bundling and drawing process. The composite wires with different sizes （Φ3.0 mm, Φ2.7 mm, Φ2.5 mm） were selected, and the core filament morphology as well as the microstructure of Cu-Nb interfaces with different sizes was characterized by SEM; then the evolution and the characteristics of the core filament and the microstructure of Cu-Nb interfaces under multi-size conditions were discussed. Finally, based on a-e and R-T curve, the evolution mechanism of property caused by size change was analyzed. Results show that when the diameter of the sample is Φ2.5 mm, the strength of composite wire approaches 1.1 GPa and the conductivity reaches 74%IACS.