Influence of strontium and lanthanum simultaneous addition on microstructure and mechanical properties of the secondary Al-Si-Cu-Fe alloy

In order to refine the secondary phases and the α-Al grain in Al-Si-Cu-Fe alloy, the Sr and La elements were added into the melt separately or simultaneously. The separate addition of Sr or La element could remarkably refine the grain, but the needle like secondary phase still existed. The simultaneous addition of Sr and La elements could refine both the secondary phase and α-Al grain