Precipitation behavior and mechanical properties of a novel Cu–2Fe-0.5Ti alloy produced by thermos-mechanical treatment

Abstract

The effect of the multi-stage thermo-mechanical treatment on the microstructure and properties of a Cu–2Fe-0.5Ti alloy (wt.%) was investigated. After repeated thermos-mechanical treatment, the alloy has the yield strength, tensile strength, elongation, electrical conductivity and softening temperature of 521 MPa, 554 MPa, 5.9%, 70.4 %IACS and 550 °C, respectively. The nano-scale Fe2Ti and γ-Fe precipitates, accompanying with some submicron-scale primary Fe2Ti phase, are found in the aged alloy. The orientation relationship between the nano-scale Fe2Ti precipitate and the Cu matrix is Fe2Ti [1‾ 21‾ 6]//Cu [01‾ 1] (with a small deviation) and Fe2Ti (02 2‾1‾)//Cu (200), while that between the nano-scale γ-Fe precipitate and the Cu matrix is γ-Fe [110]//Cu [110] and γ-Fe (111)//Cu (111), respectively. The precipitation of Fe2Ti and γ-Fe phase contributes to the improvement of the electrical conductivity and mechanical properties of the alloy. The strengthening mechanisms of the designed alloy is mainly grain boundary strengthening, dislocation strengthening and precipitation strengthening.