Application of high magnetic fields in inorganic materials processing

Abstract

Application of high magnetic fields in materials processing has started. A high magnetic field enhances not only a Lorentz force in a weak electric current but also a magnetization force in non-magnetic materials. The main results obtained from the application of a high magnetic field to the processing of several materials is reviewed. These include the alignment of particles in a composite coating as an example of a Lorentz force and the separation of inclusions in a molten metal for mass transport using magnetic force. Orientation of crystals of non-magnetic materials using magnetization force is mentioned. The orientation was conducted in such processes as electro-deposition, vapour-deposition, solidification, baking, slip-casting and precipitation.

Texturing by cooling a metallic melt in a magnetic field

“…Precise calculations of this time have been made under various assumptions [25]. Homogeneous nucleation cannot explain crystallization occurring slightly below T m ; if homogeneous nucleation occurred, the nucleation time would be minimum at T = T m /3!…”

Microstructure and Microtexture Formation of AZ91D Magnesium Alloys Solidified in a Static Magnetic Field

“…After a nucleus is yielded, the anisotropic magnetization energy of the hcp nucleus in a magnetic field DE, can be expressed as [22] DE ¼ VÁDvÁB field and that of the easy magnetization axis; and l 0 is the permeability in free space. It is worth noting here that, because of the absence of the values of v c and v a,b for the AZ91D alloy, the data for pure Mg are employed, because the alloy is primarily Mg based, which is 1.313 9 10 -6 cm 3 AEmol -1 at 14 K, 1.459 9 10 -6 cm 3 AEmol -1 at 78 K, and 1.824 9 10 -6 cm 3 AEmol -1 at 293 K. [23] Because Mg has unpaired electrons and, thus, has a positive molar susceptibility of 13.1 9 10 -6 cm 3 AEmol -1 , it shows a temperature dependence varying roughly as 1/T.…”

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

“…Recently, the research of high magnetic fields (HMFs) has extended to almost all the material science fields with the development of superconducting magnet technology. Now, the application of HMF is expected as one of promising technologies in material processing [6,7]. Control of the orientation and alignment during solidification process by the imposition of an HMF became an attractive method because of the remarkable effects of magnetic field on the solute redistribution [8,9] and crystal orientation [10].…”