Refer to the latest calculated Al-Si phase diagram:
S.-M. Liang, R. Schmid-Fetzer,Phosphorus in Al–Si Cast Alloys: Thermodynamic Prediction of the Alp and Eutectic (Si) Solidification Sequence Validated by Microstructure and Nucleation Undercooling Data Acta Mater. 72 (2014) 41-56. doi: 10.1016/j.actamat.2014.02.042.
Experiments Review paper:
J. Murray, A. McAlister,The Al-Si (Aluminum-Silicon) System J. Phase Equilib. 5 (1984) 74-84. doi: 10.1007/bf02868729.