Thermodynamic Effects of Alloying Elements on Solid-State Interfacial Reactions in a Multicomponent System: Theoretical Treatment and Application in SiCf/Ti Composites

Alloying elements have an important effect on phase formation in solid-state chemical reactions. From the viewpoint of thermodynamics, applying the Miedema model and Kohler equation, a thermodynamic model for a solid-state multicomponent system was presented. Using this model, the activity of Ti in SiC f /Ti composites was evaluated, and the influence of different alloying elements on the interfacial chemical reactions in SiC f /Ti composites at high temperature was investigated from a thermodynamic viewpoint. The calculation results showed that most alloying elements, such as Al, Sn, Ni, Fe, Cu, Mn, Cr, Mo, and V, can reduce the activity of Ti and hinder the interfacial chemical reactions in SiC f /Ti composites, but an alloying element such as Nb can decrease the stability of the interfacial chemical reactions in SiC f /Ti composites, in most cases.