Liquid structure of Al–12.5% Si alloy modified by antimony

A high-temperature X-ray diffractometer has been used to measure the structure factors and the coordination numbers at different temperatures of liquid Al–12.5% Si alloy with various additions of Sb. Radial distribution functions (RDFs), the nearest neighbor atomic distances, and the coordination numbers of eutectic Al–12.5% Si have been studied before and after being modified by Sb. The results show that a prepeak exists on the structure factor curve. Sb in liquid Al–Si alloys promotes the aggregation and nucleation of Si atoms, decreases the supercooling of solidification, and finally modifies the size and shape of the Si phases in the solid state.