Relationship between the intrinsic coercivity and the phases of Nd-(Dy)-Fe-B sintered magnets

Journal Article · Mon Apr 15 04:00:00 EDT 1991 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.347767· OSTI ID:5493148

Kim, K Y; Lee, D G; Jeung, W Y; Kang, I K ^[1]

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1. Division of Metals, Korea Institute of Science and Technology, Seoul 136-791, Korea (KR)

The magnetic properties of sintered Nd-(Dy)-Fe-B magnets prepared with different annealing conditions have been investigated. Thermomagnetic analysis was carried out on the sintered and annealed Nd-(Dy)-Fe-B magnets in the temperature range of room temperature to 320 {degree}C. The coercivity of gas-quenched Nd{sub 14.1}Fe{sub 78.3}B{sub 7.6} magnets after annealing for 1 h at temperatures between 600 and 900 {degree}C is higher by 3 kOe than the furnace-cooled one after annealing. Thermomagnetic analysis found that the sintered Nd{sub 14.1}Fe{sub 78.3}B{sub 7.6} magnet consists of the Nd{sub 2}Fe{sub 14}B phase as well as an unknown magnetic phase ({ital A}{sub 1}) with {ital T}{sub {ital c}} around 150 {degree}C. The annealed magnets consist of two unknown magnetic phases ({ital A}{sub 1},{ital A}{sub 2}) and the Nd{sub 2}Fe{sub 14}B phase with a {ital T}{sub {ital c}} of 150, 240, and 305 {degree}C, respectively. Thermomagnetic analysis also showed that the {ital M}{sub {ital r}} value of the {ital A}{sub 2} phase in the gas-quenched Nd-Fe-B magnet was higher than that of the furnace-cooled one. These results seem to indicate that increase of coercivity is related to the formation of the {ital A}{sub 2} phase.

• OSTI ID: 5493148
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 69:8; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
ANISOTROPY
ANNEALING
BORON ALLOYS
COERCIVE FORCE
DYSPROSIUM ADDITIONS
DYSPROSIUM ALLOYS
HEAT TREATMENTS
IRON ALLOYS
MAGNETISM
MAGNETS
MATERIALS
NEODYMIUM ALLOYS
PERMANENT MAGNETS
RARE EARTH ADDITIONS
RARE EARTH ALLOYS
SINTERED MATERIALS
THERMOMAGNETISM