R-T-B BASED SINTERED MAGNET

• Main Authors: ITAKURA MASARU, NAKAMURA MICHIHIDE
• Format: Patent
• Language: English; Japanese
• Published: 05.03.2020
• Subjects: ALLOYS; BASIC ELECTRIC ELEMENTS; CASTING; CHEMISTRY; ELECTRICITY; FERROUS OR NON-FERROUS ALLOYS; INDUCTANCES; MAGNETS; MAKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; METALLURGY; PERFORMING OPERATIONS; POWDER METALLURGY; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; TRANSFORMERS; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS; WORKING METALLIC POWDER

To provide an R-T-B based sintered magnet capable of effectively suppressing abnormal grain growth by forming metal borides at locations other than grain boundary triple points.SOLUTION: The R-T-B based sintered magnet includes: a main phase, including a rare earth element R, a metal element T composed of a material in which Fe or a part of Fe is substituted by Co, boron, and a boride-forming element M which is a metal element excluding the rare earth element and the metal element T, and forms a boride, consisting of crystal grains of the R-T-B based alloy; and a boride phase composed of a compound phase on the basis of a boride of the boride-forming element M generated on a preferential growth surface of the main phase crystal grains.SELECTED DRAWING: Figure 3 【課題】粒界三重点以外の場所にも金属ホウ化物を形成することで、異常粒成長を効果的に抑制することができるＲ−Ｔ−Ｂ系焼結磁石を提供する。【解決手段】希土類元素Ｒと、ＦｅまたはＦｅの一部をＣｏで置換したものよりなる金属元素Ｔと、ホウ素と、希土類および金属元素Ｔを除く金属元素であり、ホウ化物を形成するホウ化物形成元素Ｍと、を含有し、Ｒ−Ｔ−Ｂ系合金の結晶粒よりなる主相と、主相の結晶粒の優先成長面に生成した、ホウ化物形成元素Ｍのホウ化物を基本とする化合物相よりなるホウ化物相と、を有するＲ−Ｔ−Ｂ系焼結磁石とする。【選択図】図３