PRECIPITATE FORMATION AND GRAIN REFINEMENT OF MG-AL-SN ALLOY DURING HOT DEFORMATION

摘要

Magnesium alloys are very popular in the automobile industrydue to its high strength to weight ratio. However, the use ofcommercial magnesium alloys as sheet is limited by roomtemperature ductility. One way to improve the ductility may beto form precipitates during hot rolling. These may delaydynamic recrystallization, possibly leading to grain refinement,which is known to improve ductility. Equilibrium diagramsobtained from thermodynamic modeling software FactSage wereused to design Mg-3Al-2Sn alloy, which should form Mg2Snprecipitates during hot rolling temperatures around 300 °C. Toinvestigate this prediction, the alloy was cast in a copper mouldand precipitates formation characteristics were studied by usingoptical microscope (OM), scanning electron microscope (SEM)equipped with an energy-dispersive X-ray spectroscopy (EDS).