Solidification velocity of undercooled Ni–Cu alloys

Evidence for an extensive, undercooling-mediated transition in growth orientation, and novel dendritic seaweed microstructures in Cu–8.9wt.% Ni

“…This is confirmed by a log-log plot of the data, which demonstrates two distinct linear trends. Velocity-undercooling relationships of this type have been previously reported in the Ni-Cu system by Algoso et al [22] whilst investigating the Ivantsov solution with marginal stability arguments (IMS) [23]. However, in this instance, plateaus in the velocity-undercooling relationship were observed on either side of the sharp increase.…”

Grain refinement in bulk undercooled Fe81Ga19 magnetostrictive alloy

“…Based on some of the results of undercooling experiments [19], it is well known that the solidification velocity increases rapidly with increasing undercooling which always results in the increasing of strain energy stored in the solidified crystals. When the undercooling exceeds 200 K, the strain energy arising from rapid solidification process and the resulting crystalline defects is higher than the critical strain energy for recrystallization in some of local regions.…”

Phase-field investigation on the non-equilibrium interface dynamics of rapid alloy solidification

“…The experimental evidence for Ni-B alloys by Eckler et al [40] showed that this critical undercooling, ∆T * , strongly depends on the alloy composition; higher solute concentration results in higher ∆T * . In addition, several experimental data [47,48] show a plateau may appear at a velocity for lower than ∆T * .…”

“…This question still remains far from fully answered even though there have been several accounts and conjectures that point to the reason of the growth mode change at ∆T * such as; residual oxygen [47], effects of the anisotropy of kinetic interfacial mobility and change of the solute diffusion field due to the dramatic change of morphology such as dendrite to cell (or seaweed structure) transition and side branch development [60], termination of the steady state dendritic growth [60,61,62], and transition from solutal-controlled growth to thermal-controlled growth [63,64] which has been described above. Although the modeling results could be in good agreement with experimental data, those are limited to the description of steady state dendritic growth.…”