Effect of Superheating Melt Treatment on Mg2Si Particulate Reinforced in Al-Mg2Si-Cu In situ Composite

As one of the advanced engineering materials, Al-based composite reinforced with Mg2Si phase has been assigned to be a potential candidate in the manufacture of automotive products, especially those that require high temperature applications. Superheating melt treatment with various temperatures and holding times are shown to cause alteration of primary Mg2Si reinforced particulate that subsequently would improve the mechanical properties of the in situ composite. This was investigated via microstructural and thermal analysis observation. Superheat temperature at 950 °C with 15 minutes holding time has presented an adequate modification effect with skeleton structure of Mg2Si particles faded and transformed into fine polygonal shape, accompanied with decrease in size. In addition, the thermal analysis result has shown increment in nucleation temperature, TN compared to unmodified composite indicating the modification of particles is allocated with this composite melt treatment. This modification of structure is believed capable to enhance the strength properties of the in situ composite that could meet the application requirements.