Strength of deformation processed Cu–Fe–Ag in situ composites

Three Cu–Fe–Ag in situ composites, i.e. Cu–14 wt.%Fe–1 wt.%Ag, Cu–14 wt.%Fe–3 wt.%Ag and Cu–11 wt.%Fe–6 wt.%Ag, were prepared by cast and drawn process. Strength of the composites was investigated in detail. The results show that the presence of Ag can refine the primary Fe dendrites, leading to much higher strength of Cu–Fe–Ag composites, which reached 1578 and 1357 MPa for Cu–14Fe–3Ag and Cu–11Fe–6Ag respectively at η = 6.1, however that of the same processed Cu–12 wt.% Fe is only 978 MPa. Strength of Cu–Fe–Ag can be expressed as σ = 1319 × λ− 1 / 2 + 57 × CFe–M1 / 2 + ΔσAg, where λ is filament spacing, CFe–M is the Fe content in the matrix and ΔσAg is strengthening effect of Ag in the matrix. As Ag content is lower, ΔσAg = 100 × CAg 1 / 2 and as it is near or beyond 6 wt.%, ΔσAg should be determined by specific experiment due to a second-stage work hardening of the matrix. The calculated strength of Cu–Fe–Ag composites fits the experimental results well.