Possibilities of Fe-RICH phases elimination with using heat treatment in secondary Al-Si-Cu cast alloy

The mechanical properties of Al-Si-Cu cast alloy are strongly dependent upon the morphologies, type and distribution of the second phases. The skeleton like – Al15(FeMn) 3Si2 and needles - Al5FeSi phases were observed in experimental material AlSi9Cu3. The Fe-rich phases morphology was affected with applying two types of heat treatment, T4 and T6, which caused positive changes of mechanical properties especially ultimate tensile strength, gives that for as cast state was Rm = 211 MPa, than at optimum T4 (515 °C/ 4 hours) was Rm = 273 MPa and at optimum T6 (515 °C/ 4 hours with artificial aging 170 °C/ 16 hours) was Rm = 311 MPa.