Effect of Thermomechanical Processing on the Microstructure and Properties of a Cu-Fe-P Alloy

• Published in: Journal of materials engineering and performance Vol. 24; no. 4; pp. 1531 - 1539
• Main Authors: Dong, Qiyi, Shen, Leinuo, Cao, Feng, Jia, Yanlin, Liao, Kaiju, Wang, Mingpu
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.04.2015
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Corrosion and Coatings; Engineering Design; Materials Science; Quality Control; Reliability; Safety and Risk; Tribology; property; precipitate; microstructure; Cu-Fe-P alloy; heat treatments
• ISSN: 1059-9495; 1544-1024
• DOI: 10.1007/s11665-014-1352-6

A Cu-0.7Fe-0.15P (wt.%) alloy was designed, and its comprehensive properties, especially electrical conductivity and temper-softening resistance of the designed alloy, were higher than those of traditional Cu-Fe-P alloys. The microstructure of this alloy was investigated with optical microscopy, scanning electron microscopy, and transmission electron microscopy. The particle of secondary phase was confirmed to be Fe 2 P with x-ray spectroscopy and digital diffractogram. By virtue of precipitation hardening and work hardening, the tensile strength and electrical conductivity of Cu-0.7Fe-0.15P alloy were 498 MPa and 62% IACS, respectively. The electrical conductivity of this alloy can be up to 92% IACS due to the complete precipitation of Fe 2 P. After repeating the cold rolling and aging process for three times, the tensile strength, elongation, and conductivity of this alloy were 467 MPa, 22%, and 78% IACS, respectively. Due to the low driving force of recrystallization and the pinning effect of fine dispersed Fe 2 P, the alloy with low deformation rate showed excellent softening resistance. The designed alloy can be used as a high-strength, high-electrical-conductivity lead-frame alloy.