A thermodynamic assessment of the Pr-Al system

Optimized descriptions of the phase diagram and thermodynamic properties of the Pr-Al system have been obtained from experimental thermodynamic and ph ase diagram data by means of the computer program THERMO-CALC based on the least squares method, using models for the Gibbs energy of individual phase s. The system contains six intermetallic compounds. The calculated standard enthalpies of formation of Pr3Al, Pr2Al, PrAl, PrAl2, PrAL(3), Pr3Al11 are : -25.4, -33.5, -44.0, -54.9, -47.5, and -42.3 kJ/mol, respectively. A cons istent set of thermodynamic parameters was derived. Optimized and experimen tal data are in good agreement.