Formation of halo in Sb-InSb and Sn-Bi eutectic alloy systems

Halo formation in directional solidification of Ni–Ni3Nb hypereutectic alloy

“…Suk et al [6,7] proposed another model of the competitive growth of different phases in eutectic alloys to explain the formation mechanism of halo dendrites. He recognized that the growth temperature for the halo phase is much higher than the coupled growth eutectic, but lower than the primary phases.…”

“…In recent decade years, a number of papers on halo formation were published [4][5][6][7][8][9] and the early important models about halo formation were developed by Gigliotti et al [4] and Barclay et al [5], in which halo a dendrites were described to solidify at the position of the coupled zone toward the primary faceted b dendrites, which is not encompassed by the a-phase liquidus extension.…”

Halo Evolution of Hypereutectic Al‐17.5Si Alloy Treated with High‐Current Pulsed Electron Beam

“…In certain hypereutectic alloys, it has been often observed that a layer of a second phase, known as a halo, forms around primary phases under specific environmental conditions [1]. In the early 1960s, Sundquist et al [2] studied microstructures in four kinds of eutectic alloy systems, characterizing halo formation in terms of different undercoolings for the nucleation of two phases.…”

“…Yilmaz and Elliott [4] interpreted the formation of Al halos in pure Al-Si and Sr modified Al-Si alloys during directional solidification by means of this model, where an Al halo was formed around eutectic Si and primary Si. Suk et al [1,5] also proposed a modified model to interpret the formation mechanism of halo dendrites. They reckoned that the growth temperature for the halo phase is much higher than the coupled eutectic growth but lower than the primary phases.…”