A phase-field model with antitrapping current for multicomponent alloys with arbitrary thermodynamic properties

The development of accurate and efficient computational tools for phase transformation is a prerequisite in order to predict the microstructure evolution during phase transformation in engineering alloys. Even though the antitrapping phase-field model (PFM) has been developed and is increasingly being used for this purpose, it has been limited to dilute binary alloys. In this study, the antitrapping PFM was extended to multicomponent systems with arbitrary thermodynamic properties. We showed that at the condition of vanishing chemical potential jump, the antitrapping term in the multicomponent diffusion equation remains unchanged with the case of binary dilute alloys. We then derived the relationship between the phase-field mobility and the real interface mobility at the thin interface limit, and showed that the multicomponent effect in the relationship can be expressed in a concise matrix form.