A thermodynamic study of liquid Fe-Si-B alloys : an influence of ternary associates on a liquid → glass transition

Knudsen-cell mass spectrometry and the integral variant of effusion method have been applied to investigate the thermodynamic properties of liquid Fe-Si-B alloys at temperatures from 1423 to 1894 K over concentration intervals of 9-88.8 at. pct Fe. 2.6-81.4 at. pct Si, and 7.5-50 at. pct B. The activity values of the components and the Gibbs energy of the Fe-Si-B melt formation have been determined over a wide temperature-concentration range. The concentration and temperature dependences of the thermodynamic functions of liquid Fe-Si-B alloy have been described adequately within the ideal associated-solution model under the assumption that binary and ternary associates exist in the melt. The relevance of the model was tested in the undercooled region. The glass-forming ability of the melt as shown could be interpreted in terms of the thermodynamic parameters of the association reactions. A specific role of ternary interaction was clarified