Study On Properties Of Al-Er-based Heat-resistant Aluminum Alloy Conductor

The further research about thermal resistant Al-Er heat-resisting aluminum alloy conductor was carried out on the base of preliminary work. The mechanical properties, conductivity and thermal stability of Al-Er-Zr-B and Al-Er-Zr heat-resisting aluminum alloy conductor were investigated.The Al- Er-Zr-B alloy conductor exhibits superior conductivity and heat resistance. These properties have satisfied the requirement about conductivity and heat resistance in the standard of AT1 super conductive heat-resisting aluminum alloy conductor. Al-0.1Er-Zr-B has a superior conductivity at room temperature, about 62.39% IACS, which is coinciding with preliminary work.The main purpose of B elements in the Al- Er-Zr-B conductive aluminum alloy is to react with Zr element to generate Zr B2, Increase the B content had scarcely effect on the conductivity when the B:Zr ratio in the alloy already reached 2. The conductivity increased as Er content when the Er content was below 0.1wt.% in Al-Er- Zr-B conductive aluminum alloy. The addition of Er could improve the conductivity. The conductivity increased as Ce content when the Re content was below 0.1wt.% in Al-Er- Zr-B conductive aluminum alloy. The addition of Ce could lead the less improvement of conductivity comparing the addition of Er in Al-Er-Zr-B conductive aluminum alloy.The heat resistance of Al- Er-Zr conductive aluminum alloy was superior. The tensile properties, conductivity at room temperature and heat resistance changed as Zr content. Most of Zr existed in α-Al matrix as solute atoms when the Zr content was below 0.15 wt.%. The strength and heat resistance increased as Zr content rising. The elongation and conductivity decreased as Zr content increased. In Al-Er-0.2wt.%Zr conductive aluminum alloy, the most of Zr formed secondary particles. The grain refinement and increase of strength, elongation and conductivity could be gain when the 0.2wt.% Zr addition compared with 0.15 wt.% Zr addition. But the heat resistance decreased in Al- Er-Zr conductive aluminum alloy.The heat resistance and conductivity increased when over-aging treatment(210℃×8h) was carried out for Al-Er-Zr conductive aluminum alloy. The Al-0.1Er-0.05 Zr alloy conductor exhibited excellent properties: conductivity was 60.2%IACS, the temperature of 90% strength retention reached 300℃, the strength kept above 90% after serving for 40 years which is predicted by figure fitting. These properties have satisfied the requirement about conductivity and heat resistance in the standard of AT3 super conductive heat-resisting aluminum alloy conductor.