Thermodynamic modeling of the Mo-Si-B system

A thermodynamic description for the Mo-Si-B system has been developed on the basis of the constituent binaries and critically reviewed ternary experimental data. The published thermodynamic descriptions for the Mo-Si and B-Si binaries were directly used and that for the Mo-B binary was modified in the present study. A two-sublattice model, (Mo)(0.625)(B, Si, Va)(0.375), was applied to the T2 phase considering its crystal structure and homogeneity range. This model not only can describe the B substitution with Si along B/Si direction but also can accommodate the temperature dependence of the Mo content in T2. The phase stability, the liquidus projection and the solidification paths were calculated accordingly based on the currently obtained thermodynamic description and compared with the experimental results. (C) 2004 Elsevier Ltd. All rights reserved.