Transformation of Fe-rich intermetallic phases and eutectic Si morphology in Al–Si–Cu–Fe cast alloy with solution treatment

The transformation of Al₅FeSi intermetallic phase and eutectic Si morphology were studied with different solution treatment time at 510 °C. The results show that solution treatment can change the morphology of the acicular Fe phase and the eutectic silicon. As the solution time increases, the acicular Fe-rich phase and eutectic silicon gradually spheroidize, and the Fe-rich phase changes from Al₅FeSi to Al₈Fe₂Si phase. When the solid solution time is 10 h, the ultimate tensile strength and elongation are 275.6 MPa and 3.5%, respectively. The fracture mode changes from quasi-cleavage fracture to ductile fracture after solution treatment, and a large number of dimples appear in the fracture morphology. (paper)