Microstructure And Properties Of Al-Fe-Cu Alloys Prepared By Horizontal Continuous Casting And Continuous Extrusion Forming

With the rapid growth of national power industry, the demand of wire and cable for industrial construction, civil construction and urban construction increase gradually. Al-Fe-Cu alloy conductor offers significant advantages such as light weight,high electrical conductivity, and good resistance to creep and corrosion by adding alloy elements Fe, Cu, Mg, etc. Thus it has been an optimal alternative of the copper and widely used for urban building cable wires. In this paper, the X-ray diffraction(XRD),optical microscope(OM), scanning electron microscope(SEM), transmission electron microscope(TEM), tensile test, hardness test and compressed creep test were applied to study the microstructure and property of Al-Fe-Cu alloy conductor prepared by the new method including the horizontal continuous casting and subsequent Conform processes. Through the study, the pratical effect of this new method was discussed.The main results are as follows:(1) Due to the thermal dissipation condition during the horizontal continuous casting, the grain size and orientation between the transverse section and the longitudinal section are very different. As the primary second phase of Al-Fe-Cu alloy,Al3 Fe phases are mainly distributed along grain boundaries in network. The dynamic recovery(DRV) and even dynamic recrystallization(DRX) during Conform deformation induced obvious grain refinement, strain-induced precipitation of the Al7Cu2 Fe phase and the transformation of crystal orientation distribution, which led to the improved comprehensive mechanical and electrical properties.(2) The processed Al-0.63Fe-0.24 Cu alloy has better creep resistance under the condition of 90oC/76 MPa compared with pure Al and annealed Cu. The enhanced properties are attributed to the grain refinement as well as the fine and homogeneously distributed of thermally stable Al3 Fe and Al7Cu2 Fe precipitation phases. The work-hardening of a set of barriers to the cross-slip of dislocation and dislocation pinning significantly hinder the movement of dislocation, therefore obviously decreased the creep rate And the primary creep strain may comply with the logarithmic law.(3) With the increase of Fe content, the quality of Al3 Fe phase rose, the grain refined, the mechanical property including tensile strength and hardness increases.However, ductility and electrical conductivity decrease with the the increase of Fecontent. The main fracture mode of Al-Fe-Cu alloy is ductile frcture. The tensile fracture appears to be dimple. With the increase of Fe content, the quality of the dimple increases and the size decreases.