Coexistence of rod-like and lamellar eutectic growth patterns

Pseudo-4D view of the growth and form of locked eutectic colonies

“…Our observation bears some similarity to that of Refs. [87,88], wherein presence of transverse thermal gradients [88] and velocity changes [87] can destabilize the steady-pattern formation in transparent eutectics. In Ref.…”

“…In Ref. [88], the authors observed a varicose instability that prompts a coplanar transition from lamella to rod, somewhat akin to a Rayleigh instability. However, there are two key differences between their work and ours: Firstly, in their case, lamellae are stabilized only by a wall/boundary effect while rods are ordinary formed in succinonitrile-d,camphor.…”

Lamella-rod pattern transition and confinement effects during eutectic growth

“…However, while secondary instabilities do not change the basic topology of the coupled-growth patterns [9,10], the shape transformation from lamellae to rods, and the reverse one, involve the disruption, or breakup, of the triple-junction lines (trijunctions) at which the two solids and the liquid are in contact. The lamella-rod transition is thus a discontinuous process, and gives rise to highly nonlinear, particularly complex spatio-temporal phenomena [8,17,18,19,20,21,22,23,24,25]. Among key results, the lamellar breakup was shown to result from the amplification of a propagative instability that resembles a Rayleigh-Plateau instability [17,22,26].…”

“…The lamella-rod transition is thus a discontinuous process, and gives rise to highly nonlinear, particularly complex spatio-temporal phenomena [8,17,18,19,20,21,22,23,24,25]. Among key results, the lamellar breakup was shown to result from the amplification of a propagative instability that resembles a Rayleigh-Plateau instability [17,22,26]. Recently, it has been revealed experimentally that lamellar and rod-like patterns can coexist spatially in the form of large domains [22].…”

“…Among key results, the lamellar breakup was shown to result from the amplification of a propagative instability that resembles a Rayleigh-Plateau instability [17,22,26]. Recently, it has been revealed experimentally that lamellar and rod-like patterns can coexist spatially in the form of large domains [22]. Intriguingly, long lamellae were observed at a very low pulling velocity only, whereas at higher V values, rod-like patterns systematically formed.…”