Local elongation of a high Fe-containing Al-Si-Cu-Mg alloy by a deformation-semisolid extrusion process

Abstract Local elongation of Al-4.5Si-1.0Cu-0.3Mg(-1.0Fe) alloys (wt.%) produced by a deformation-semisolid extrusion process is investigated using an optical microscope, tensile tests, a transmission electron microscope, electron backscattered diffraction and X-ray diffraction. Not only uniform and but also large local elongation were confirmed in the as-extruded 1 Fe alloy. Tensile specimens survived even after showing necking and the maximum load gradually decreased from 16.7% to 28% of elongation. The correlation between fragmented Fe-IMCs and local elongation is discussed in terms of the strain distribution and dislocation density. High densities of fragmented Fe-IMCs and grain boundaries provide numerous locations for dislocation accumulation. The dislocation density ρ of the as-extruded 1 Fe alloy was estimated with different strain levels. More locations of dislocation multiplication extend the local elongation behavior of the as-extruded 1 Fe alloy.