The objective of this work was to obtain a slurry with thixotropic behavior by semi-liquid method for the application of magnesium as a light material in automobile industry. This work has been studied as a basic step for establishing a new forming process-semi-liquid forming. Magnesium alloys were prepared by a grain refining method-controlled solidification, and then heated to obtain a desired microstructure. Processing variables included the initial grain size, temperature, and holding time. Variations in intergranular and grain boundary liquid fraction were measured as functions of material temperature and holding time. With increasing the holding time, intergranular liquid fraction decreased, whereas grain boundary liquid fraction increased. The process towards spheroidisation of the solid phase was observed and the morphological changes of the slurry were expected to be calculated by LSW (Lifshitz, Slyosov, Wagner)theory. |
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