Thermodynamic assessment of B–Zr and Si–Zr binary systems

Both B–Zr and Si–Zr binary systems have been thermodynamically reassessed with CALPHAD approach. The liquid is treated as substitutional solution phase, of which the excess Gibbs energies are formulated with Redlich–Kister polynomial functions. hcp-Zr and bcc-Zr are treated by interstitial model. Terminal solution β-B is treated as the formula (B)93:(B,Zr)12 using two-sublattice model with B on the first sublattice and B, Zr on the second one. The binary intermetallic compounds, ZrB, ZrB2, ZrB12, Si2Zr, α-SiZr, β-SiZr, α-Si4Zr5, β-Si4Zr5, Si2Zr3, Si3Zr5, SiZr2 and SiZr3 are treated as stoichiometric phases. Subsequently, based on available experimental data from open literatures, optimization is performed using Parrot modules of Thermo-calc software package. And a set of self-consistent thermodynamic parameters describing each phase which appeared in these two systems have been obtained, which can reasonably reproduce the corresponding experimental data.