Dendritic growth rate in undercooled, dilute TiNi melts

A real-time synchrotron X-ray study of primary phase nucleation and formation in hypoeutectic Al–Si alloys

“…Other methods of growth rate determination include DS experiments [46][47][48][49][50][51], confocal microscopy [52][53][54], high-speed camera [55,56] or photo-diode [57,58] on levitated undercooled droplets, and microgravity experiments on organic compounds. Note that in the DS experiments the interface growth rate is governed, in part, by the rate of movement of a user-imposed thermal gradient along the specimen, and there is columnar grain growth at least in the early part of the experiment which may be followed by equiaxed growth depending upon other factors.…”

Formation of single-phase supersaturated solid solution upon solidification of highly undercooled Fe–Cu immiscible system

“…This corresponds theoretically to a transition from solute-to thermal-controlled growth, as evidenced by the current experimental observation (see Figs. [3][4][5]. The uniform microstructure at high undercooling can be explained by the formation and the occurrence of complete solute trapping if DTXDT(V D ) (see Fig.…”

“…For highly undercooled melts, non-equilibrium rapid solidification occurs, which changes the growth velocity and solidification behavior, thus gives many products that cannot be obtained under equilibrium conditions, e.g., metastable phases [1][2][3][4]. So far, thermodynamic or kinetic ways, such as levitation melting [5], molten-glass denucleation [6][7][8], melting spinning [9], gas atomization [10] and laser deposition [11], etc, have been adopted to achieve high undercooling (DT) or large supersaturation for metals or alloys.…”

Rapid phase transformation under local non-equilibrium diffusion conditions

“…[19][20][21][22]27 The prediction of LNDM that the local non-equilibrium diffusion effects lead to the sharp transition from diffusion controlled solidification to diffusionless and partitionless growth at V ¼ V D , which is accompanied by the break in the T i ðV Þ function, is consistent with experimental data. [7][8][9][10][11][12][13][14][15][16][17][19][20][21][22][23][24][25][26][27] For example, measurements of interface velocity as a function of undercooling during rapid solidification of Cu-Ni and Cu-Ni-B, 7,8 Ni-B, 9,11,14 Ag-Cu, 10 Co-Si, 11,12,14 Ti-Ni, 13 Fe-Ge (Ref. 16) and b Ni3Ge (Ref.…”

“…PDE is one of the most popular equations in mathematical physics, and it provides a good description of heat mass transfer processes in a great variety of practically important situations as long as the local equilibrium assumption holds. However, some experimental results [7][8][9][10][11][12][13][14][15][16][17] and theoretical treatments [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32]40 on rapid alloy solidification indicate that, at high solid/liquid interface velocity, the local equilibrium assumption breaks down, and the solute diffusion in the bulk liquid occurs under far from local equilibrium conditions. In this case, CIT and PDE cannot adequately describe solute diffusion in the bulk liquid, and a local non-equilibrium approach should be used.…”