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

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.

Determination of the electrical and thermal properties of Al-Sn-Zn alloys

“…In addition, Aluminum alloys have interesting electrochemical behavior and electrical properties [3][4][5][6][7][8][9][10][11]. Visible changes in the electrochemical behavior of Aluminum have been reported even when there is a small amount of Sn [5][6][7][8] or Zn [9][10][11] are introduced to it as alloying activator elements, these elements shift negative values the pitting potential of Aluminum which allowing the alloy to be used as anode material in batteries or in cathodic protection systems for underwater installations.…”