US4808224A — Method of consolidating FeNdB magnets

Claim 1

Independent Claim 164 words

In the method of treating a preform consisting essentially of FeNdB alloy particles to produce a magnet having superior magnetic properties, the steps that include: (a) removing O 2 from the preform and applying an O 2 resistant coating to the preform surface, (b) heating the coated preform to elevated temperature and in a non-oxidizing atmosphere, to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated and coated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed and to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 2

Dependent Claim 164 words

In the method of treating a preform consisting essentially of FeNdB alloy particles to produce a magnet having superior magnetic properties, the steps that include: (a) removing O 2 from the preform and applying an O 2 resistant coating to the preform surface, (b) heating the coated preform to elevated temperature and in a non-oxidizing atmosphere, to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated and coated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed and to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 3

Dependent Claim 20 words

The method of claim 1 including the initial step of forming said preform by pressurizing a mass of the particles.

Claim 4

Dependent Claim 30 words

The method of claim 2 wherein said pressurizing of the particles is carried out by locating said mass of the particles within another grain bed and pressurizing said other bed.

Claim 5

Dependent Claim 44 words

The method of claim 2 wherein said pressurizing of the particles is carried out by providing a die having a cavity, locating said mass of the particles in said cavity, and providing a plunger and displacing the plunger to pressurize said mass of particles.

Claim 6

Dependent Claim 21 words

The method of claim 2 including the step of initially displacing the particles to align them in generally the same direction.

Claim 7

Dependent Claim 16 words

The method of claim 5 wherein said displacing of the particles is effected by vibrating them.

Claim 8

Dependent Claim 11 words

The method of claim 1 wherein said coating consists of glass.

Claim 9

Dependent Claim 33 words

The method of claim 1 wherein said coating consists of glass frit in a liquid carrier vehicle, and including the step of removing the liquid carrier vehicle from the coating by vacuum application.

Claim 10

Dependent Claim 27 words

The method of claim 7 wherein said heating of the glass coated preform is carried out at a temperature of between about 700° C. and 800° C.

Claim 11

Dependent Claim 17 words

The method of claim 9 wherein said heating is contained for between about 6 to 10 minutes.

Claim 12

Dependent Claim 13 words

The method of claim 9 wherein said heating is effected by magnetic induction.

Claim 13

Dependent Claim 24 words

The method of claim 1 wherein said transfer of the heated and coated preform is carried out rapidly to pass through an air environment.

Claim 14

Dependent Claim 15 words

The method of claim 1 wherein said grain bed consists essentially of carbonaceous grain particles.

Claim 15

Dependent Claim 12 words

The method of claim 13 wherein said carbonaceous particles are resiliently compressible.

Claim 16

Dependent Claim 12 words

The method of claim 13 wherein said carbonaceous particles consist of graphite.

Claim 17

Dependent Claim 11 words

The method of claim 13 wherein said carbonaceous particles are fissured.

Claim 18

Dependent Claim 14 words

The method of claim 1 wherein said rate is between 0.1 and 0.7 TSI/sec.

Claim 19

Dependent Claim 14 words

The method of claim 1 wherein the bed consists essentially of ceramic grain particles.

Claim 20

Dependent Claim 16 words

The method of claim 1 wherein the bed consists of both ceramic and carbonaceous grain particles.

Claim 21

Dependent Claim 19 words

The method of claim 1 wherein application of pressure is held at said dwell level up to 120 seconds.

Claim 22

Dependent Claim 32 words

The method of claim 1 wherein the pressure application: (i) is about 10 TSI at the first mentioned dwell level, (ii) is between 10 and 40 TSI at the second dwell level.

Claim 23

Dependent Claim 45 words

The method of claim 1 including: (i) reducing said pressure application, at the end of a dwell interval at said dwell level, (ii) and again performing (a'), (b'), (c') and (d') steps corresponding to said (a), (b), (c) and (d) steps, upon the same preform.

Claim 24

Dependent Claim 27 words

The method of claim 22 wherein the step d 1 pressure application is carried out as in claim 15, and to the same or different dwell level.

Claim 25

Dependent Claim 9 words

The magnet produced by the process of claim 1.

Claim 26

Dependent Claim 9 words

The magnet produced by the process of claim 15.

Claim 27

Dependent Claim 9 words

The magnet produced by the process of claim 24.

Claim 28

Dependent Claim 158 words

In the method of treating a preform consisting of metallic alloy particles subject to rapid oxidation, the steps that includes: (a) removing O 2 from the preform and applying an O 2 resistant coating to the preform surface, (b) heating the coated preform to elevated temperature and in a non-oxidizing atmosphere, to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated and coated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 29

Dependent Claim 158 words

In the method of treating a preform consisting of metallic alloy particles subject to rapid oxidation, the steps that includes: (a) removing O 2 from the preform and applying an O 2 resistant coating to the preform surface, (b) heating the coated preform to elevated temperature and in a non-oxidizing atmosphere, to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated and coated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 30

Dependent Claim 138 words

In the method of treating a preform consisting of alloy particles, the steps that include: (a) applying a vitreous coating to the preform surface, (b) heating the coated preform to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated and coated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed and coating to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 31

Dependent Claim 138 words

In the method of treating a preform consisting of alloy particles, the steps that include: (a) applying a vitreous coating to the preform surface, (b) heating the coated preform to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated and coated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed and coating to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 32

Dependent Claim 17 words

The method of claim 28 wherein said coating consists of glass frit in a liquid carrier vehicle.

Claim 33

Dependent Claim 153 words

In the method of treating a preform consisting essentially of FeNdB alloy particles to produce a magnet having superior magnetic properties, the steps that include: (a) maintaining an O 2 -free environment at the preform, (b) heating the preform to elevated temperature and in a non-oxidizing atmosphere, to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed and to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 34

Dependent Claim 153 words

In the method of treating a preform consisting essentially of FeNdB alloy particles to produce a magnet having superior magnetic properties, the steps that include: (a) maintaining an O 2 -free environment at the preform, (b) heating the preform to elevated temperature and in a non-oxidizing atmosphere, to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed and to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 35

Dependent Claim 147 words

In the method of treating a preform consisting of metallic alloy particles subject to rapid oxidation, the steps that include: (a) maintaining an O 2 free environment at the preform, (b) heating the preform to elevated temperature and in a non-oxidizing atmosphere, to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Claim 36

Dependent Claim 147 words

In the method of treating a preform consisting of metallic alloy particles subject to rapid oxidation, the steps that include: (a) maintaining an O 2 free environment at the preform, (b) heating the preform to elevated temperature and in a non-oxidizing atmosphere, to facilitate subsequent bonding of the particles during their consolidation, (c) providing a consolidation zone containing a grain bed and transferring the heated preform to said zone to be embedded in the grain bed, (d) applying pressure to the grain bed sufficient to be transferred via the bed to the heated preform, thereby to consolidate the preform, said application of pressure to the grain bed carried out to increase to a dwell level at a rate that minimizes fracturing of the consolidated preform, said application of pressure held at said dwell level for at least several seconds and subsequently increased to a second dwell level.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1992-02-28	1992-08-29	1993-02-28	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1996-02-28	1996-08-29	1997-02-28	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2000-02-28	2000-08-29	2001-02-28	$7700.00	Window Closed / Lapsed

Method of consolidating FeNdB magnets

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