Phase alignment and crystal orientation of Al3Ni in Al–Ni alloy by imposition of a uniform high magnetic field

Effects of high magnetic fields on solidified structures of Mn-90.4 wt% Sb hypoeutectic alloy

“…It is widely recognized that a high magnetic field can exert three effects on a system, that is, Lorentz force, magnetic force and magnetization. On the basis of these three effects, investigations on non-or unidirectional solidification under high magnetic fields have shown that high magnetic fields can induce aligned microstructures [6][7][8]; change the equilibrium partition coefficient [9,10], phase transformation temperature [11,12] and the distribution of solute elements [13,14]; decrease the diffusion coefficient [15,16]; and induce thermoelectromagnetic convection [17,18].…”

Solidified Structure Control of Metallic Materials by Static High Magnetic Fields

“…[21][22][23] The movement of the particles was remarkably restrained by the Lorentz forces either acting on the particles or on the convection in the liquid matrix. More homogeneous microstructures of some monotectic 21) and eutectic 23) systems were thus obtained. Theoretical analysis was also carried out to elucidate such effect.…”

“…21) By considering the fact that Lorentz force still has a vertical component with the imposed magnetic field and exhibits a similar effect to that of viscous resistance, the terminal velocity of the particles was deduced in terms of the Hartman number. Such quantitative description has been used to characterize the solidification processes of Cu-Pb monotectic 21) and Al-Ni eutectic 23) systems in high magnetic fields, during which the migration of the Cu-rich drops and primary Al 3 Ni particles was strongly affected by the Lorentz force respectively. A high magnetic field was also found to reduce the local flows around the solidifying front caused by solute rejection and thermocapillary effect.…”

“…In fact, the Al 3 Ni crystals have been evidenced to be oriented in a magnetic field up to 4.4 T with their c-axes parallel to the imposed magnetic field by other researchers using X-ray diffraction techniques. 23,36) In 1991, de Rango et al 37) successfully fabricated oriented YBa 2 Cu 3 O 7 materials at high temperature by solidification in a 5 T magnetic field and proven the possibility for in-situ producing oriented structure during solidification in a high magnetic field. Following their study, the oriented structures were obtained in a series of alloy systems such as Sm-Co, 38,39) Bi-Mn, 40,[41][42][43] Bi-Zn, 44) Al-Fe, 45) Mn-Sb, 46,47) and Al-Ni 23,36,48) alloys and some high-temperature superconductor materials [49][50][51] by solidification in a high magnetic field.…”

“…By applying a high magnetic field to a slow solidification process, the primary phase of an alloy can be aligned either parallel or perpendicular to the magnetic field direction. Such alignment of primary phase has been realized in a series of binary and ternary systems such as Al-Ni, 23,36,48,57) Mn-Bi, [40][41][42] Mn-Sb, 46,47,58) Al-Fe 45) and Al-Si-Fe 41) alloys. Figure 4 shows the typical microstructures of Al-11mass%Si-2mass%Fe alloy solidified at 0 T and 5 T.…”