Extension and Application of Miedema’s Model in O and S Containing Melts and Alloys

Abstract

Combined Miedema's model with experimental data provided by Kleppa, the parameters of oxygen and sulfur which were satisfied with Miedema's model were derived: Oxgen: electronegativity 7.04, electronic density 6.03, molar volume 4.59; Sulfur: electronegativity 5.8, electronic density 3.24, and molar volume 6.97. In comparison with results from literature, those parameters had been turned out to be highly reasonable to Miedema's model. The mean absolute percentage error of enthalpies of formation of binary alloying oxides and sulfides were 36.8%, 34.2% respectively. Combining Ding's model, the activities and interaction coefficients between oxygen and other elements of Fe- based alloying melt in 1873 K were derived and further compared with available experimental data. Calculated results were confirmed to be in good agreement with available experimental data, except some special cases. Therefore the long-term problem related with the parameters of oxygen and sulfur for Miedema's model has been resolved successfully by this method. In particular, the special cases Nb, Pt, Ag-their electronegativities(4.05, 5.65, 4.35) were revised to be 4.31, 5.57 and 4.17, respectively, and the revised parameters were much more reasonable than the original parameters.