TABLE OF CONTENTS Analysis of non-equilibrium solidification in ternary and other multicomponent alloys is much more difficult than for binary alloys. Depending upon solidification conditions (first of all, solidification rate) different types of deviations from equilibrium conditions can develop. Let us consider several specific examples of deviation from equilibrium for solidification processes occurring in real three- and four-component systems.
Assuming that the relations and rules described above will also hold for multicomponent systems, we have conducted analyses of non-equilibrium solidification for aluminum alloys of some three- and four-component systems containing iron. These results are mostly related to alloys containing (Al) formed directly after solidification; however, the same methods could be applied with equal success to different alloy systems.
Inasmuch as this system is key for understanding the behavior and properties of so-called technical aluminum, there are many studies exploring non-equilibrium phase compositions and diagrams. In particular, the distribution of phase domains in as-cast condition was conducted by Philips [40]. It follows from his study that a significant part of the concentration field is occupied by four- and five-phase alloys (Figure 2.17a) the most obvious proof of non-equilibrium nature of the corresponding alloys. The concentration fields of primary solidification of Al 3Fe, Al 8Fe 2Si, and Al 5FeSi undergo shifts toward lower concentrations of Si (Figure 2.17b) as a function of the solidification rate V c [104]. As a...
