METHOD OF MANUFACTURING RARE EARTH-IRON-NITROGEN BASED MAGNET POWDER, AND RARE EARTH-IRON-NITROGEN BASED MAGNET POWDER AVAILABLE BY THE SAME

• Main Author: YAMAUCHI MITSURU
• Format: Patent
• Language: English
• Published: 30.08.2012
• 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

PROBLEM TO BE SOLVED: To provide a method of manufacturing rare earth-iron-nitrogen based magnet powder, and rare earth-iron-nitrogen based magnet powder that is available, in which the rare earth-iron-alloy powder is uniformly nitrided by utilizing a reduction/diffusion method, for improved magnetic characteristic.SOLUTION: The method of manufacturing rare earth-iron-nitrogen based magnet powder which is represented by a formula (1) includes a step in which rare earth oxide powder, iron powder, and a reductant for reducing the rare earth oxide are mixed, which is then baked by heating in a non-oxidizing atmosphere by a reduction/diffusion method, to provide a reduction/diffusion reactive product containing a rare earth-iron mother alloy, and a step in which the obtained rare earth-iron mother alloy is subjected to a nitriding process. The manufacturing method is characterized by performing a heating/drying process under such a condition as an ignition loss component of the rare earth oxide is reduced to 0.1 mass% or less, before the rare earth oxide is mixed with the iron powder and the reductant. RFeN...(1), where R is one kind or two or more kinds of rare earth elements, and a, b are atom% to satisfy 4≤a≤18, and 10≤b≤17.