Tensile properties and microstructural characteristics of indirect rheoformed A356 aluminum alloy

The effects of rheoforming parameters such as the rheoforming temperature and pressure on the tensile properties of H-shaped components were examined. An H-shaped component is useful for practical investigation into the influence of different wall thicknesses on the microstructural and mechanical properties. A simulation study on the effect of forming pressure on the die filling was conducted using the DEFORM-3D package, and the results were compared with that obtained using the actual rheoforming. The semisolid slurries were prepared by employing the electromagnetic stirring (EMS) technique. The components were rheoformed at different forming conditions and their tensile properties in the center and side positions were evaluated and linked to the corresponding microstructure. The tensile properties remained approximately constant when the rheoforming temperature was increased from 580 degrees C to 590 degrees C, but was followed by a substantial reduction at 600 degrees C. Moreover, the tensile properties in the center and side positions were distinct Increasing the rheoforming pressure from 200 MPa to 250 MPa had a harmful effect on the elongation values, whereas the effect on the ultimate tensile strength values was limited. This trend could be linked to the increase in prevalence of internal defects such as the liquid segregation. (C) 2012 Elsevier B.V. All rights reserved.