Study of microstructure evolution and properties of Cu-Fe microcomposites produced by a pre-alloyed powder method

• Published in: Materials & Design Vol. 126; pp. 64 - 72
• Main Authors: Wang, Fenglin, Wakoh, Kimio, Li, Yunping, Ito, Shun, Yamanaka, Kenta, Koizumi, Yuichiro, Chiba, Akihiko
• Format: Journal Article
• Language: English; Japanese
• Published: Elsevier Ltd 15.07.2017; Elsevier BV
• Subjects: Cu-Fe microcomposite; Electrical conductivity; Hot consolidation; In situ technique; Microstructure evolution; Strength; Cu-Fe microcomposite; Hot consolidation; Electrical conductivity; In situ technique; Strength; Microstructure evolution
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2017.04.017

In this work, Cu-based microcomposites were fabricated by powder metallurgy of gas-atomized Cu-15wt% Fe alloy powder, followed by drawing to various strains. The microstructure evolution and the resultant mechanical and electrical properties were investigated by scanning electron microscopy, electron backscatter diffraction, and tensile testing, among other techniques. The results indicated that during drawing, the Fe phase evolved into nanoscale filaments along the longitudinal direction. With increasing drawing strain, both the Cu grains and the Fe filaments were refined gradually, giving rise to a mean thickness of approximately 25nm for the Fe filaments at a total strain of 4.0. The iron oxides particles formed due to contamination of oxygen maintained unchanged during drawing process. In addition, it was found that an intermediate aging during the drawing can significantly enhance the electrical conductivity of the microcomposites without sacrificing their strength. The present process involving an initial powder with a homogenous distribution of Cu and fine Fe phases makes it possible to obtain microcomposites with an ideal combination of electrical and mechanical properties at lower drawing strain, compared to those produced by conventional casting methods. [Display omitted] •Fe-reinforced Cu microcomposites are fabricated by PM followed by a drawing.•Fe particles evolved inhomogenously at low drawing strain.•Aging during drawing results in increase in conductivity without sacrificing strength.•Finer and Fe filaments could be obtained at lower drawing strain than casting route.•Cu-Fe microcomposites in present study show superior property than traditional route.