Comparison of mechanical characteristics between semi-liquid state and semi-solid state in Al-Mg alloys

In our previous works, tensile test devices for both semi-liquid and semi-solid aluminum alloys were developed. In this report, comparison of mechanical properties such as ultimate tensile strength (UTS) and fracture strain between semi-liquid and semi-solid Al–Mg alloy was examined. Difference of the mechanical properties will be caused by the microstructural change during heating process in the tensile test of semi-liquid alloy. By constant load creep test to the semi-liquid alloy, about 90% deformation of permanent and 10% of elastic deformation were found. Thus, in the thermal-stress analysis, solid–liquid co-existence aluminum alloy should be dealt as visco–elastic or viscoelasto–plastic material rather than elasto-plastic material.