A Thermodynamic Model for Representation Reaction Abilities of Structural Units in Full Composition Range of Fe–Si Binary Melts Based on the Atom–Molecule Coexistence Theory

Abstract

A thermodynamic model for calculating the mass action concentrations of structural units in Fe-Si binary melts based on the atom-molecule coexistence theory, i.e., the AMCT-N i model, has been developed and verified through comparing with the reported activities of both Si and Fe in the full composition range of Fe-Si binary melts at temperatures of 1693, 1773, 1873, and 1973

Retraction: Representation of Reaction Ability for Structural Units in Fe–Al Binary Melts

“…Therefore, the atom-molecule coexistence theory, i.e., AMCT, can be applied to describe the structural characteristics of Fe-Al binary melts. The hypotheses of the developed AMCT-Ni model for Fe-Al binary melts can be briefly summarized as follows: 1) the Fe-Al binary melts at elevated temperature are composed of seven structural units including two atoms as Fe and Al as well as five molecules as Fe3Al, FeAl, FeAl2, Fe2Al5 and FeAl6 according to the phase diagram of Fe-Al binary melts 18,21) and viewpoints described in Section 1 from the literature; 11) 2) each structural unit occupies its independent position in Fe-Al binary melts; 3) the elements of both Fe and Al in Fe-Al binary melts will take part in reactions of forming five molecules as Fe3Al, FeAl According to the definition of mass action concentrations Ni for structural units based on the AMCT 11,[18][19][20] for metallic melts or the IMCT 22,23) , N1 (NFe) and N2 (NAl) based on the mass action law were summarized in Table 2.…”

“…The mass conservation equations of two atoms as Fe and Al in 100-g Fe-Al binary melts can be established based on the above-mentioned definitions 11,[18][19][20]22,23) of ni, Ni, and Σni as follows According to the principle that the sum of mole fraction of all structural units in a fixed amount of metallic melts under equilibrium condition is equal to unity as 1, the following equation can be established (-).... (4) The governing equations of the developed AMCT-Ni thermodynamic model for calculating the mass action concentrations Ni of structural units in Fe-Al binary melts are comprised by the equation group of Eqs. (3) and (4).…”

“…Mole Number ni and Mole Fraction of xi of Structural Units in Fe-Al Binary Melts It has been described in Section 2.2 that the calculated equilibrium mole numbers ni is an important parameter to represent mass content of structural units in Fe-Al binary melts under equilibrium, like mole fraction xAl of Al or mole fraction xFe of Fe, according the AMCT 11,[18][19][20] or the IMCT. 22,23) The relationship of the calculated equilibrium mole number ni of each structural unit against mole fraction xAl of Al shown in Fig.…”

“…Several attempts [24][25][26] can well describe the thermodynamic properties of metallic melts on the concept of ionic or molecular constituents associated with artificial parameters, and most of the regressed artificial parameters were obtained by experimental results. 20) Although various experimental technique were adopted to measure the activity of Al and Fe in liquid Fe-Al alloys, to the knowledge of the present authors, no prediction model was established to predict or evaluate the activity of Al and Fe in liquid Fe-Al alloys. In this study, the AMCT-Ni thermodynamic model for calculating the mass action concentrations Ni of structural units in Fe-Al binary melts in the temperature range from 1 573 K to 1 873 K has been developed without any regressed parameters.…”

Determination of Activity Coefficients of Elements and Related Thermodynamic Properties of FeSi Binary Melts Based on the Atom–Molecule Coexistence Theory

“…According to the atom and molecule coexistence theory (AMCT) for metallic melts, [56][57][58][59][60][61][62] the mass action concentrations N i of structural units in Fe-Si binary melts have been calculated in a previous publication. [63] The good agreement between the measured [11] activity a R, Si of Si and the calculated [63] mass action concentration N Si of Si as well as the good agreement between the calculated [11,63] activity a R, Fe of Fe and the calculated [63] mass action concentration N Fe of Fe suggest that the calculated [63] mass action concentrations N Si of Si or N Fe of Fe can substitute the measured [11] activity a R, Si of Si or the calculated [11,63] activity a R, Fe of Fe to represent the reaction ability of Si and Fe with ideal accuracy. It should be emphasized that the essential cores of the AMCT [56][57][58][59][60][61][62] for metallic melts are similar with the ion and molecule coexistence theory (IMCT) [56,57,[64][65][66][67][68][69][70][71] for metallurgical slags.…”