Method for making permanent magnets of Mn-Al-C alloys.

摘要

Anisotropic Mn-AI-C alloy magnets exhibiting excellent magnetic characteristics in multipolar magnetization are described. The magnets are obtained by subjecting a polycrystalline Mn-Al-C alloy magnet, which is rendered anisotropic, to compressive working or extrusion at a temperature of from 530 to 830°C while keeping restrained at least part of the hollow billet along its length so that the at least part is prevented from suffering compressive deformation until fed into a compressive working region. Permanent magnets obtained by the method are also described.