Abstract:The solidification curves of Al-8.5Fe, Al-8.5Fe-1.7Fe, Al-8.5Fe-1.7Si-1.3V alloys were examined by DTA under the condition of slow cooling rate, the phase constitutes were examined by OM and XRD. The results show that, under slow cooling rate, the phases in Al-8.5Fe alloy are mainly α(Al) and Al₁₃Fe₄, the phases in Al-8.5Fe-1.7Si alloy are mostly α(Al), Al₁₃Fe₄, α-AlFeSi, β-AlFeSi, and comparing to Al-8.5Fe-1.7Si alloy, no other phases form in the Al-8.5Fe-1.3V-1.7Si alloy, but the chemical compositions of the phases are changed and the thermal stability of α-AlFeSi phase and β-AlFeSi phase is improved, due to the partial substitution of V for Fe atoms. The phase formation was calculated by Thermo-calc software at equilibrium condition, the calculated results were agreement with the experimental results.

Key words: solidification curve; thermodynamic analysis; heat-resistant Al alloy