Metastable A[sub 1] phase in Al-doped Nd-Fe-B magnets

Conference · Mon Nov 01 04:00:00 EST 1993 · IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States)

OSTI ID:6895486

Politano, R; Missell, F P ^[1]; Nozieres, J P

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1. Univ. de Sao Paulo (Brazil). Instituto de Fisica

The role of the metastable A[sub 1] phase in the coercivity of Al-doped Nd-Fe-B magnets has been investigated in a magnet enriched in both Nd and Al. The as-sintered magnet (intrinsic coercive field [sub i]H[sub c] = 3.6 kOe) contains an additional phase with Curie temperature [Tc]=180 C, while the annealed (600 C/1h) magnet ([sub i]H[sub c] = 12.1 kOe) does not. As-cast ternary alloys with compositions Nd(20-x)at.%Fe-xat.%Al(x=1-10) show the metastable A[sub 1] phase with reduced [Tc], but annealed alloys show the [mu] and [delta] phases of the Nd-Fe-Al system. Quaternary Nd-Fe-B-Al alloys were also studied. The disappearance of the ferromagnetic phase with [Tc] = 180 C is associated with the decomposition of A[sub 1]. The magnetic properties of [delta] are discussed and the transformation kinetics of A[sub 1] are studied.

• OSTI ID: 6895486
• Report Number(s): CONF-930416--
• Conference Information: Journal Name: IEEE Transactions on Magnetics (Institute of Electrical and Electronics Engineers); (United States) Journal Volume: 29:6Pt1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360104* -- Metals & Alloys-- Physical Properties
42 ENGINEERING
420200 -- Engineering-- Facilities
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ALLOYS
ALUMINIUM ALLOYS
BORON ALLOYS
COERCIVE FORCE
CURIE POINT
DATA
DOPED MATERIALS
EXPERIMENTAL DATA
INFORMATION
IRON ALLOYS
IRON BASE ALLOYS
MAGNETIC PROPERTIES
MAGNETIZATION
MAGNETS
MATERIALS
NEODYMIUM ALLOYS
NUMERICAL DATA
PERMANENT MAGNETS
PHASE STUDIES
PHYSICAL PROPERTIES
RARE EARTH ALLOYS
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE