Crystallographic effect of a high magnetic field on a solidified hypoeutectic Zn–Al alloy

Abstract

Hypoeutectic Zn-4.45 wt% Al solidified under a high magnetic field was investigated crystallographically. With the field, the primary zinc-rich phase is distributed homogeneously and orients with the c axis perpendicular to the magnetic field direction. These results are attributed to the magnetic viscosity resistance force and the magnetocrystalline anisotropy of zinc, respectively. The orientation modification also leads to a preferential alignment of the flat-shaped primary dendrites. Furthermore, with the field, the eutectic phase shows an orientation character similar to that of the primary phase. This arises from its continuous growth with the primary phase. In addition, a specific crystallographic orientation relationship ({0001} || {111} , h1210i || h110i ) exists in some of the eutectics (between the eutectic zinc-rich and aluminium-rich phases). However, this orientation relationship is related to the distribution of primary dendrites, which originates from the independent nucleation of the pseudo-primary phase attached to the primary dendrites.

Morphological and Crystallographic Characterization of Primary Zinc-Rich Crystals in a Ternary Sn-Zn-Bi Alloy under a High Magnetic Field

“…Therefore, it is of fundamental interest to study its growth under HMFs. In other work, it has been shown that the primary zinc-rich crystals in Zn-Al [13] and Zn-Sn [14,26] alloys have a dendritic form (preferentially grow along < 101 0 > and/or <0001>) and can be preferentially aligned and oriented by HMFs. According to some recent work, the primary zinc-rich crystals in ternary Sn-Zn-Bi solder alloys usually exhibit a needle-like morphology in two dimensions [27].…”

“…Crystals 2017, 7, 204 2 of 10 (usually negligible in conventional magnetic fields), thereby imposing more abundant effects on the structures of the alloys [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]. It has been found that the HMFs could orient and align the structures [13][14][15][16][17], increase the phase transformation temperature [19], enhance the magnetic coercivities [16], suppress the diffusion of solute elements [21], modify the orientation relationship between the eutectics [22], and change the solid-liquid interface morphologies [23]. Hexagonal close-packed zinc is characterized by large solid-liquid interfacial energy anisotropy [24,25] and magnetocrystalline anisotropy [13,14].…”

“…It has been found that the HMFs could orient and align the structures [13][14][15][16][17], increase the phase transformation temperature [19], enhance the magnetic coercivities [16], suppress the diffusion of solute elements [21], modify the orientation relationship between the eutectics [22], and change the solid-liquid interface morphologies [23]. Hexagonal close-packed zinc is characterized by large solid-liquid interfacial energy anisotropy [24,25] and magnetocrystalline anisotropy [13,14]. Therefore, it is of fundamental interest to study its growth under HMFs.…”

“…Hexagonal close-packed zinc is characterized by large solid-liquid interfacial energy anisotropy [24,25] and magnetocrystalline anisotropy [13,14]. Therefore, it is of fundamental interest to study its growth under HMFs.…”

Composite coatings formed by plasma electrolytic oxidation and using telomeric tetrafluoroethylene solutions

“…Coating formation on metal and alloy surfaces is one of the most common ways to protect items from environmental impacts [1][2][3][4] and to specifically func tionalize their surfaces [5][6][7]. Plasma electrolytic oxi dation (PEO) is an outstanding route to form protec tive coatings [see 8-10 and other references].…”