Experimental investigation and thermodynamic calculations of the Al–Cu–Sb phase diagram

Phase diagram of the Al–Cu–Sb ternary system was investigated experimentally by DTA and SEM–EDS methods and theoretically by CALPHAD method. The liquidus projection, invariant equilibria, three vertical sections: Sb–Al0.5Cu0.5, Al–Cu0.5Sb0.5 and Cu–Al0.5Sb0.5 as well as isothermal sections at 400 °C and 200 °C were predicted using COST MP0602 thermodynamic database. In addition, phase transition temperatures of the selected samples with compositions along calculated isopleths were experimentally determined using DTA. Experimentally obtained phase transition temperatures were compared with the results of thermodynamic calculation. Predicted isothermal sections at 400 °C and 200 °C were compared with the results of the SEM–EDS analysis from this work. In both cases, a good agreement between theoretical calculations and experimental results was obtained.

► Experimental and thermodynamic assessments of the Al–Cu–Sb system were carried out.
► Three vertical sections: Sb–Al0.5Cu0.5, Al–Cu0.5Sb0.5 and Cu–Al0.5Sb0.5 were defined.
► Calculated horizontal section was validated by SEM–EDX analysis of alloy samples.
► Liquidus surface projection was calculated and invariant reactions were defined.
► Good agreement between the calculations and experimental data was obtained.