The Formation Mechanism and Characteriza

A modified Al-Si alloy containing up to 15 wt.% Si has been obtained from the reaction of sodium fluosilicate (Na2SiF6) with molten aluminum. This study aimed to estimate the mechanism of the reaction between Na2SiF6 and molten aluminum for the production of Al-Si alloys, while investigating the effects of temperature, Na2SiF6/Al weight ratio, and reaction time on the formation of Al-Si alloy. We performed thermodynamic calculations, kinetic studies, and assessed the reaction rate. The results indicated the thermodynamic feasibility of the reaction and that it may be controlled chemically. This study specifically optimized the factors affecting the preparation of modified Al-Si alloy from sodium fluosilicate reduction with molten aluminum, revealing that a temperature of 950 °C and a reaction time of 20 to 25 minutes with an appropriate Na2SiF6/Al weight ratio corresponded to the desired silicon percentage. The microstructural analysis utilized Light Optical Microscopy (LOM), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDX), showing the transformation of needle-like silicon to fine fibrous structures. Furthermore, the modified alloys demonstrated improved wear characteristics as well as increased tensile strength and hardness.