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‐Al‐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 φ, and is found to consist of the following Gaussian distribution term and constant. P(φ) = 3.42 exp [−φ²/(2×30.8²) ] + 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 [001] single fiber texture. The inverse pole figure indicates that among twelve {111} 〈112〉 twin systems, four twin systems which preserve CuAu I type superstructure are responsible for the formation of this texture.