Estimation of Activity Interaction Parameters in Fe-S-j Systems

Abstract

It is important to know the activity interaction parameters between components in melts in the process of metallurgy. However, it’s considerably difficult to measure them experimentally, relying still to a large extent on theoretical calculations. In this paper, the first-order activity interaction parameter (esj) of j on sulphur in Fe-based melts at 1873 K is investigated by a calculation model established by combining the Miedema model and Toop-Hillert geometric model as well as considering excess entropy and mixing enthalpy. We consider two strategies, with or without using excess entropy in the calculations. Our results show that: (1) the predicted values are in good agreement with those recommended by Japan Society for Promotion of Science (JSPS); and (2) the agreement is even better when excess entropy is considered in the calculations. In addition, the deviations of our theoretical results from experimental values eS(exp)j-eS(cal)j depend on the element j’s locations in the periodic table.

A General Model for Solutes Activity Interaction Parameters in Dilute Metallic Solutions

“…In the past, many AIPs models have been proposed. [8][9][10][11][12][13][14][15][16] For example, Tanaka 17) used a free volume theory to derive a model to calculate AIPs in metal-based melts; Ueno and Waseda 10,15) applied the pseudopotential theory coupled with the free energy of the hard sphere model to predict the AIPs; Ding 8,9) at the early 1990s firstly suggested a method using the geometric model coupled with the Miedema model 18) as well as other thermodynamic relations to predict the AIPs in alloy systems. Recently, Matsumiya 11) predicted the AIPs in Silicon-based melts by combining ab-initial calculation and Monte Carlo simulation.…”