INFLUENCE OF PHOSPHORUS ADDITION ON THE MICROSTRUCTURE OF IN-SITU Al-25 WT.% Mg2Si COMPOSITE

INFLUENCE OF PHOSPHORUS ADDITION ON THE MICROSTRUCTURE OF IN-SITU Al-25 WT.% Mg2Si COMPOSITE

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Part of #INFLUENCE OF PHOSPHORUS ADDITION ON THE MICROSTRUCTURE OF IN-SITU Al-25 WT.% Mg2Si COMPOSITE# :

Publishing year : 2012

Conference : The first international conference and the 6th joint conference of the Iranian Metallurgical Engineering Association

Number of pages : 11

Abstract: In current research, the effects of different concentrations of P (0, 0.05, 0.1, 0.3, 0.5, 0.7 and 1% wt.) On microstructures of Al-25% wt. Mg2Si composites have been investigated. Microstructural examination was performed using optical and scanning electron microscopy (SEM). As-cast microstructure analysis of the composite indicated that the primary Mg2Si phases are very coarse with a mean size of 200m. Also, the results indicate that P add changes the morphology of primary Mg2Si from irregular to polygonal or spherical shapes and reduces the size of primary Mg2Si particles from 200m to 20m in 1% wt. Added P specimen. Furthermore, the morphology of eutectic Mg2Si phases changes from fibriform to short fibriform or dot-like. With addition of P, it reacts with Al to produce particles of AlP phase. The AlP particles can be suitable sites for heterogeneous nucleation of Mg2Si. It is believed that P add has a strong influence on the nucleation process of the primary Mg2Si particles and the subsequent formation of the -Al phase and the eutectic matrix.