R-T-B BASED PERMANENT MAGNET

• Main Authors: NAKANE MAKOTO, MASUZAWA KIYOYUKI
• Format: Patent
• Language: English; Japanese
• Published: 14.06.2018
• Subjects: ALLOYS; BASIC ELECTRIC ELEMENTS; CHEMISTRY; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; INDUCTANCES; MAGNETS; METALLURGY; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide an R-T-B based permanent magnet showing high residual magnetic flux density Br and coercive force HcJ.SOLUTION: There is provided an R-T-B based permanent magnet in which, R is a rare earth element, T is an element other than a rare earth element, B, C, O or N, and B is boron. R at least includes Tb, and T at least includes Fe, Cu, Co and Ga. A total of R content is 28.05-30.60 mass%, Cu content is 0.04-0.50 mass%, Co content is 0.5-3.0 mass%, Ga content is 0.08-0.30 mass%, and B content is 0.85-0.95 mass%, relative to 100 mass% of a total mass of R, T and B. The R-T-B based permanent magnet shows a concentration distribution in which Tb concentration reduces from the outside to the inside of the R-T-B based permanent magnet.SELECTED DRAWING: Figure 1 【課題】 残留磁束密度Ｂｒおよび保磁力ＨｃＪが高いＲ−Ｔ−Ｂ系永久磁石を提供する。【解決手段】 Ｒが希土類元素であり、Ｔが希土類元素，Ｂ，Ｃ，ＯおよびＮ以外の元素であり、Ｂがホウ素であるＲ−Ｔ−Ｂ系永久磁石である。Ｒとして少なくともＴｂを含有し、Ｔとして少なくともＦｅ、Ｃｕ、ＣｏおよびＧａを含有する。Ｒ、ＴおよびＢの合計質量を１００質量％として、 Ｒの合計含有量が２８．０５質量％〜３０．６０質量％、Ｃｕの含有量が０．０４質量％〜０．５０質量％、 Ｃｏの含有量が０．５質量％〜３．０質量％、Ｇａの含有量が０．０８質量％〜０．３０質量％、Ｂの含有量が０．８５質量％〜０．９５質量％である。Ｔｂの濃度分布が、Ｒ−Ｔ−Ｂ系永久磁石の外側から内側に向かって低下する濃度分布である。【選択図】 図１