Microstructure and mechanical properties of a Cu-Fe-Nb alloy with a high product of the strength times the elongation

Abstract

The tradeoff between the strength and fracture elongation in the high strength Cu-Fe alloys has been a research focus recently. A Cu-10 wt.%Fe-0.5 wt.% Nb alloy was designed and fabricated by casting and thermomechanical treatment to high strength and elongation. Microstructure evolutions and properties variations of the studied alloy during cold-drawing and cold rolling were investigated. After annealed at 400 ℃ for 1 h and further aged at 450 ℃ for 8 h, the ultimate tensile strength, elongation, product of the strength times the elongation (PSE), and electrical conductivity of the cold-drawn studied alloy were 736 MPa, 36 %, 22.82 GPa%, and 48.74 %IACS, respectively. Nanocrystals, Nb precipitates, and Fe fibers were detected in the studied alloy, which contributed to the high strength and the high fracture elongation. These findings provide essential understandings of the effects of the niobium on Cu-Fe system alloys, and the designed Cu-Fe-Nb alloy with high strength and fracture elongation could fulfill some requirements of the electronic and electrical industry.