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 semiliquid 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.