Refinement of Hypereutectic Al–Si Alloy by a New Al–Sc–P Master Alloy

Abstract

In this article, a novel Al–Sc–P master alloy with ScP particles was successfully synthesized. The XRD result identifies that the Al–1Sc–1P master alloy is composed of two phases, i.e. α-Al and ScP. The microstructure analysis shows that ScP present grey granular particles with 6.5 μm in size. The reason for the excellent refining performance of this master alloy is discussed based on the chemical kinetics theory. During the solidification process, P which dissolved homogeneously in the melt bonded with Al and precipitated in the form of AlP, providing heterogeneous nucleation sites for primary Si.