A thermodynamic description of the Al–Mo–Si system

The thermodynamic reassessment of the Al–Mo–Si system was performed using the CALPHAD technique. The solution phases (liquid, bcc, fcc and diamond) were modeled as a substitutional solution. The compounds AlMo3 in the Al–Mo system and Mo3Si in the Mo–Si system had the same A15 crystal structure, and were treated as one phase and described by a two-sublattice model (Al,Mo,Si)(Al,Mo)3. The compound Mo5Si3 with D8m crystal structure was treated as the formula Mo0.5(Mo,Si)0.125(Al,Mo,Si)0.375 in the Al–Mo–Si system. Other compounds, Al63Mo37, Al8Mo3, Al3Mo, Al4Mo, Al17Mo4, Al22Mo5, Al12Mo and Al5Mo in the Al–Mo system, MoSi2 in the Mo–Si system, and ternary compounds C40 and C54 were treated line compounds (Al,Si)mMon in the Al–Mo–Si system. Based on the published experimental isothermal sections and the liquidus surface projection, the Al–Mo–Si system was re-optimized, and a set of self-consistent thermodynamic parameters was obtained.