MANUFACTURING METHOD OF PERMANENT MAGNET

To provide a new manufacturing method of a permanent magnet that does not use a rare earth element that does not perform nitriding treatment and has a risk of future resource risks and rising prices.SOLUTION: A manufacturing method of a permanent magnet includes a first step of obtaining a first alloy which includes more than 37 atomic% and less than 46 atomic% of Fe, more than 30 atomic% and less than 40 atomic% of Mn, and more than 20 atomic% and less than 30 atomic% of Ga, satisfies Fe>Mn (1) (in the formula (1), Fe is the content of Fe in atomic%, and Mn is the content of Mn in atomic%.), and a main phase of a face-centered cubic lattice (fcc) structure, and a second step of performing heat treatment of heating the first alloy at temperature of 450°C or more and 500°C or less in a vacuum or an inert gas to obtain a second alloy whose main phase has a tetragonal structure.SELECTED DRAWING: Figure 2 【課題】窒化処理を行わず、将来的な資源リスク及び価格高騰リスクがある希土類元素を使用しない新たな永久磁石の製造方法の提供。【解決手段】Ｆｅ：３７原子％超４６原子％未満、Ｍｎ：３０原子％超４０原子％未満、Ｇａ：２０原子％超３０原子％未満、を含み、且つ下記式（１）を満たし、主相が面心立方格子（ｆｃｃ）構造である第一合金を得る第一工程と、Ｆｅ＞Ｍｎ 式（１）（式（１）において、Ｆｅは原子％で示すＦｅの含有量であり、Ｍｎは原子％で示すＭｎの含有量である） 前記第一合金を真空中又は不活性ガス中で４５０℃以上５００℃以下の温度で加熱する熱処理を実施し、主相が正方晶構造である第二合金を得る第二工程と、を含む、永久磁石の製造方法。【選択図】図２