Strength and conductivity of Cu-9Fe-1.2X (X = Ag or Cr) filamentary microcomposite wires

Abstract

In this study, strength and electrical conductivity of Cu-9Fe-1.2X (X ϭ Ag or Cr) microcomposite wires obtained by cold drawing combined with intermediate heat treatments have been investigated. During cold working, the primary and secondary dendrite arms are aligned along the drawing direction and elongated into filaments. The addition of Ag was found to reduce the filament spacings at the given draw ratio throughout the drawing processing. The ultimate tensile strength and the conductivity of the Cu-Fe-Ag microcomposites were higher than those of Cu-Fe-Cr microcomposites, suggesting the refinement of the filaments is more effective than the strengthening of the filaments in strengthening the microcomposites. The strength of Cu-Fe-Xi microcomposites is dependent on the spacing of the Fe filaments in accord with a Hall-Petch relationship. The fracture surfaces of all the specimens showed ductile-type fracture and iron filaments occasionally observed on the fracture surfaces. The good mechanical and electrical properties in Cu-Fe-Ag wires may be associated with the more uniform distribution of the filaments than in Cu-Fe-Cr wires. The increase of the conductivity in Cu-Fe-Ag and Cu-Fe-Cr after intermediate heat treatments is attributed to the precipitation of Fe, Cr, or Ag particles, which dissolved during heavy deformation processing.

Copper-Iron Filamentary Microcomposites

“…[1±10] The scale of the final microstructure is determined by the cold-working strain and the initial dendrite size. [2,4,8] In Table 1, the strength and conductivity of Cu±Fe microcomposites reported in the literature are summarized. Initial Cu±Fe billets can be fabricated by either casting [8,11,13,15] or powder processing.…”

“…[2,4,8] In Table 1, the strength and conductivity of Cu±Fe microcomposites reported in the literature are summarized. Initial Cu±Fe billets can be fabricated by either casting [8,11,13,15] or powder processing. [2,9,10,12] The size of the dendrites will depend on the solidification rate and the nature of the solid/liquid reaction.…”

“…However, the addition of Cr to the Cu±Fe system may improve the corrosion resistance. [8,13] Early studies have been mostly directed at binary Cu±Fe microcomposites containing over 15 vol.-% Fe. [2,9±12] Recently Hong and co-workers investigated the effect of Cr, Ag, Ni, and Co on the microstructure and physical properties of Cu± Fe microcomposites.…”

“…[2,9±12] Recently Hong and co-workers investigated the effect of Cr, Ag, Ni, and Co on the microstructure and physical properties of Cu± Fe microcomposites. [8,14,15] In this article, the properties of Cu±Fe microcomposites will be summarized and the possible ways of improving the properties of Cu±Fe microcomposites for more general applications will be discussed.…”

Enhanced Strength and Electrical Conductivity of Cu–8Fe Composite by Adding Trace Ag and P

“…Recent research has reported that a third alloying element can refine the microstructure and enhance the properties of Cu-based composites. Song et al 14,15) reported that the 0.1 mass% Ag refined the primary Fe dendrites in the as-cast microstructure of Cu9 mass%Fe. Gao et al 16,17) reported that Cu11Fe 6Ag (mass%) in situ composites had higher tensile strength and conductivity (1020 MPa/70.5%IACS, respectively) at strain of 10 compared to Cu12Fe.…”