DIFFUSION INTERACTION MODEL IN AL-FE2O3 SYSTEM INCLUDING THE FORMATION OF INTERMETALLIC PHASES

Abstract

In this paper, we consider the problem of interaction of a spherical iron oxide particle with an aluminum melt surrounding it. A comparison of two different approaches to describing the interaction in the Al-Fe₂O₃ system suitable for various temperature intervals is presented. The first of these is the problem with the volume reaction. This problem is solved numerically by front straightening method. The counter-sweep method and an implicit difference scheme are used. The second variant of the model corresponds to sequential reactions and is typical for reactive diffusion theory. This is applicable to another temperature interval when intermetallide does not transfer to the melt. This problem is solved in the quasi-stationary approximation. The results show that both models give similar dynamics of the appearance of Al₂O₃ oxide. Different rates of intermetallide accumulation reflect different reaction mechanisms in different temperature intervals. Both approaches can be applied to describe the process of phase formation in other, more complex systems.