Crystal orientation and its formation process of an anisotropic Mn-Al-C permanent magnet

Abstract

An easy axis distribution and a crystal texture in a warm extruded anisotropic Mn-AI-C magnet were determined by X-ray diffraction analyses. Resulting values in (001) pole density are treated by introducing a normalization condition in order to determine the quantitative values. The distribution is expressed only as a function of tilt angle 4>. and is found to consist of the following Gaussian distribution term and constant. P(4)) = 3.42 exp [-4>2/(2X30.8 2 ) 1 + 0.11. Magnetically measured Mr/Ms = 0.88 is significantly higher than 0.74, the value calculated from this total distribution when assuming that the magnetization in every grain points in the direction of each easy axis. The crystal texture is approximated by [OOIJ single fiber texture. The inverse pole figure indicates that among twelve {Illl <112) twin systems, four twin systems which preserve CuAu I type superstructure are responsible for the formation of this texture. PACS numbers: 75.50. -y, 81.40.Ef J.

Magnetic-Field-Induced Acceleration of Phase Formation in τ-Mn-Al

“…This was a result of the ε-τ solid-phase transformation. The ε-τ transformation was reported to be a massive transformation 33) . During the massive transformation, ε-phase with disordered hcp structure became ordered hcp structure, following the hcp-L1 0 transformation.…”

Bulk Mn-Al-C permanent magnets prepared by various techniques

“…19 The tp for the hot-deformed magnet is calculated to be 0.26 and the texture developed is in the plane perpendicular to the deformation direction. In the case of Mn-Al-C magnets prepared by extrusion, Koch et al, 1 Ohtani et al, 4 Sakamoto et al 20 and Bittner et al 19 reported texture formation in the axis parallel to the extrusion direction. Figure 4 shows the XRD patterns of the magnets prepared by the three processes.…”

Texture analysis of ultra-high coercivity Sm2Co7 hot deformation magnets*

“…This manifests that during the HD process, the grains tend to form a concentrated orientation relationship while forming the texture, and this orientation relationship is related to the mechanism of the texture formation of the grain rotation and recrystallization. [19][20][21][22] The results of XRD, EBSD, and misorientation analysis consistently show that the increase in deformation can promote the formation of (001) texture. Good (001) texture is primary for the permanent magnet materials to improve remanence.…”