Microstructure Evolution and Properties Tailoring of Rheo-Extruded Al-Sc-Zr-Fe Conductor via Thermo-Mechanical Treatment.

Di Tie,Fei Gao,Lufei Yan,Yu Wang,Jin Zhang,Xiang Wang,Haifeng Liu,Yang Zhao,Renguo Guan,Zhihui Cai

doi:10.3390/ma13040845

Abstract

Low-cost heat-resistant Al-Sc-Zr-Fe conductor wires were successfully manufactured by continuous rheo-extrusion process, and the mechanical and conductive properties of the materials were analyzed and compared after three different thermo-mechanical treatment methods. The coarse plate-shape Al3Fe phase transformed to small sized rod-like phase after solid solution treatment at 630 °C for 21 h. Direct aging treatment at 300 °C for 24 h led to the refinement and spheroidization of Al3Fe phase with a diameter of 200 nm. After the subsequent aging treatment at 300 °C for 24 h, the tensile strength and conductivity of the alloy wire significantly increased due to the homogeneous precipitation of the coherent spherical Al3(Sc, Zr) phase with an average size of 15 nm. The tensile strength, elongation, and conductivity of the alloy conductor wire after optimized thermo-mechanical treatment reached 165.7 MPa, 7.3%, and 60.26% International Annealed Copper Standard (IACS), respectively. The thermal resistance of the present alloy wire was superior to that of standard AT1 type alloy conductor according to IEC international standard.

Highlights

IntroductionAluminum alloys have shown great potential for use as an electrical material owing to its light weight, good mechanical properties, suitable corrosion resistance, and excellent electrical conductivity [1,2]
Aluminum alloys have shown great potential for use as an electrical material owing to its light weight, good mechanical properties, suitable corrosion resistance, and excellent electrical conductivity [1,2].Since the heat resistant effect of Zr addition into Al matrix was found, the development of the Al-Zr alloy conductor has drawn the attention of conductive material researchers [3]
The plate-shape Al3 Fe phase in the continuous rheo-extrusion (CRE) Al-Sc-Zr-Fe alloy conductor transformed into rod-like and elongated during solid solution treatment (SST) at 630 ◦ C with a length of 300 nm

Summary

Introduction

Aluminum alloys have shown great potential for use as an electrical material owing to its light weight, good mechanical properties, suitable corrosion resistance, and excellent electrical conductivity [1,2]. Since the heat resistant effect of Zr addition into Al matrix was found, the development of the Al-Zr alloy conductor has drawn the attention of conductive material researchers [3]. Ocenasek and Slamova denoted that the addition of Sc and Zr in Al alloys could improve the recrystallization temperature of the alloys, improved the heat resistance and mechanical properties of the alloy at elevated temperatures [5]. The high thermal stability of Al3 (Sc, Zr) phase makes the Al-Sc-Zr alloy materials have a huge potential of application at higher temperatures [8]

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Discussion

Conclusion