The structures expected in a simple ternary eutectic system: Part 1. Theory

Multiphase solidification in multicomponent alloys

“…McCartney, Jordan and Hunt [97,98] were the first to extend the Jackson-Hunt theory for binary alloys [73] to univariant eutectics. They derived an expression for the relationship between interface undercooling, growth velocity and eutectic spacing, that for minimum undercooling yields l 2 v = K. For calculation of the constant K the materials properties i.e.…”

“…Rinaldi et al [95] and McCartney et al [97] proposed a constitutional supercooling criterion for defining the stability limit for planar univariant eutectic growth, by assuming that a Mullins-Sekerka (MS) type instability applies for the transition from planar to cellular eutectic growth. The constitu-tional supercooling criterion can then be formulated in terms of the third, segregating component ''C'' [95]:…”

“…eutectic cells and dendrites (fingers) in ternary and multicomponent alloys is in the early stage of development (see Section 4.1). Himemiya et al [110,135,136] were the first to attempt at deriving approximate analytical solutions for growth of competing morphologies in a ternary eutectic alloy system, based on the classification and strategy proposed by McCartney et al [97]. The growth model for two-phase eutectic cells and dendrites with rod-like intracellular eutectic structure [135] is based on the assumption that the undercooling can be expressed as a sum of the eutectic undercooling and the constitutional undercooling of the cellular tip.…”

“…For alloys outside the groove the expression proposed by McCartney at al. for ternary single phase dendrites is used [97]. Reality is much more complex but despite of the many assumptions used, Himemiya's model can be a guide for experiment design, whenever rod-like eutectics are concerned.…”

Theoretical and numerical study of lamellar eutectic three-phase growth in ternary alloys

“…. In preliminary works, the occurrence of lamellar structures has been reported in experiments in massive samples [10][11][12][13][14][15][16]. The spatio-temporal evolution in ternary eutectic systems was observed in thin samples (quasi-2D experiments) in both metallic [17] and organic systems [18].…”