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The effect of boron on the magnetic properties of AlNiCo 5 permanent magnet alloys
Materials
Chemistry
and Physics,
13 (1985)
489-495
489
SHORT COMMUNICATION
THE EFFECT OF BORON ON THE MAGNETIC
OF AlNlCo
PROPERTIES
5
PERMANENT MACWET ALLOYS
s.
SZYMURA
Institute of Phyeics, 42-200 CrQstochowa
Technics1
of Ferrous
Metallurgy,
Institute Received
March
20
1985;
University,
Zewadrkiego
Gliwice
44-100
accepted
Al.
22 April
(Poland
19,
)
1985
ABSTRACT The Investigation of the effect of boron (0 - 1.0 wt%) on the magnetic properties of magnetically hard Alnlco 5 allo of equiaxial grain structure has shown that the addition of t Kla element in the amount up to 0.003 wt% Increases the coercive force end maxlmua magnatic ener y product but decreases tha renenant induction. Tha addition o 3 boron * 0.003 wt% causes the decrease of those
properties
INTRODUCTION NotwIthstanding
[ 11,
Alnlco
netariala
the
type for
applicatlone Alnico
type
tically the
logical also riala.
materlela
magnetic
an important
magnets
used
are
alloys
the
group
In various
of
technical
of
magnetic
practice
theory
composition
properties
the in
basic
aateriala
properties
far
are
in
and have
of
from those
the theorb
[I]. of
alloying
elements
common waye
moat
propertlaa
to improve
A ayetemetited
02%0584/85/$3.30
renagnetiratlon the
on magnetic
obtelned
and physlcal applied
concerning
Nevartheleaa
introduction
melt
of
In addition,
influence
predicted
Tha
solved
alloys.
aetabillahed.
Alnico
new hard
conetltute
production are
type
heat-treatment been
still
of
[ 2,3].
Many problems the
alloys
the
appearance
of
functional analysis
used
and
for
aetala.
their
addition
laproving
the
An Identical
qualities of
tha
influence
of
aethod
aagnetic of
0 Elsevier Sequoia/Printed
into
techno-
certain
la
mataale-
in The Netherlands
490
ments on magnetic alloys data
properties of
the eddition
permanent
of
of
The purpose
properties
of
magnetically
herd
type were published
on the effects
those of
snd mechanical
of Alnico
[ 5,6], and recently 808% new S, Nb, Hn, Cs-miech@etel end Se on
Ti.
the
Alnico
the present
of
ragnst
boron
llloy
5
work is
were discussed
(7-101.
to Investigate
on the nagnetic
properti%s
the effect of Alnlco
5
efloys.
EXPERIMENTAL Material The chemical
of
conpoeltion
-25Ni-24Co-3Cu-x8
with
OS
means of % vacuum induction diameter.
of
25 nin
rat% which
was 8ufficiently
phbSe,
since
this
tic
propertlse
of
a magnetic
fibld
which
was 8llOWed
the
was ennealsd
method
of
in
were
melted
cylinder
of
effect
Intensity,
OCCUr8 , was oarrfed fisld
by
15 mm
by heating
910 K for
4 hrs
8t
a
of
ths
cooling
(15 K*nin-‘)
during
which decon-
out
was again
et
on ths nagne-
from 1$70 to 8M
removed
and cooling
down to room temperature.
freely
at
out
prseipitation
. Controlled
(ii]
magnetic
and at 830 K for
Then the 15 hre.
applied method8 of prOperti68
M8t8llographlc
StUdi
invebtigstion and of
by a norms1 metallographic
cture
of
propertIe
type AEG p%rmeamoter with treatm%nt surface
oxidized
on poll8hed Macro-
by the method given
were determin8d tha accurecy
the epocimens
the me8surem8nt8
8nd niorOstructUrer
t8ChniqUe.
88mples were reveslsd
The magnstlc
covered
tha macro-
wer8 p8rfOrm8d
parsd
ence of
was (Sl-x)Fe-8Al
(5 K*%ec-I)
to prevent
240 kA*n*’
th8 nagnbtic
heat
end ca8t
by cooling
high
the alloy
to proceed
The applied of
elloye
The alloys
phase has a detrimental
pO8&tiOn Of the oLph88e
Teat
furnace
and was followed
In
alloy
wt%.
the apeclmene was carried
1520 K for
K, aft8r
tested
The boron was sdded es ferro-boron.
Homogenization
r
the
x G 1.0
were
layer8
of
ground
seCtlOn8 1121,
in
by me8ne of the order
to ellafnate
on the magnetic
pre-
%nd nicrostru8 MJ-55
1%. After
the
influ-
propertiee.
RESULTS AND DISCUSSION The dependence of and mexlmun magnetic
loy
of
equiaxiel
grain
coercfve energy
force product
structure
(He),
remanent induction
((SH)max)
in
the Alnlco
on the proportion%1
content
i Srf 5 alof
L"O
2.1f3
10-2
1o4 B [wt %I
t Fig. 1. Influence of boron residual induction ( (BH)max ).
(Bf)
boron
in
Is
sented
presented
It
is
apparent
and
addition magnetic
force ( tic) , product
on the coercive maximum energy
Fig.
1. From the
that
the
shape
character
of
and
the
range
curves of
pre-
the
changes
magnetic properties are significantly dependent on the boron in the alloy. The addition of boron up to 0.003 wt% inc-
of
content reases ie
both
more
product.
For
decrease. sted
boron
The
range
The
Hc and
pronounced
of
observed
re
of
additions
of
Induction of
changes
Increase
x a
the
of
the
coercive
maximum magnetic
0.003
wt% both
decreases
within
force energy
Hc and
(BH) max
whole te-
the
boron.
of
magnetic
structure with
the with
remanent
be connected the
and
compared
addition
of equiaxial grain should
(BH)nax as
the
properties
resulting changes
alloy because, as Is seen
from
of the
of
macro-
from
our
Alnico
addition and
results
alloy
5 of
boron
micro-structu(see
Figs
2
Fig. with
2. Hacroatructure boron additions,
of (b)
Alnico 0.0051
5 alloy without boron wt%, (c) 1.0 wt%
(a),
and
493
Fig. with
3 W&crostructure bot’on additions,
of Alnico (bf 0,003
5 alloy without wt%, (c) 0.0038
boron (a), and wt%, Id] 0.015 wt%
494
and 3). 8lloY
these grain
appeared
Size
also
chengee
negligibly
wt% but
the grains
x==0.003
rut% (see
finenent
of
qI8gnetiC
induction
decreesee
magnetic
induction
flux
tization
direction.
also
caused
phese
are
due to the addition
strongly
examples
grains
on grain
a” phase
preeent
the
content;
at
boron
T phase
addition
is
of
of
the magnetic
small
boron
of
non-magnetic
its
8bOVO 0.003
of
losses
of
to the aagne-
properties
the alloy
is
~~0.003
The
depends
on
wt% the amount
increases
wt% (compare
7
[i2].
significantly
Content
fraction
The re-
causes
high-temperature
of
the alloy
the boron but
normal
content 2).
the the
the aegnetic
properties in
due to
boundaries
The decrease
of
The
~~~0.003
boron
in Fig.
es one
the alloy
boron.
Content
when the
macroetructufes of
by the presence
worsening
8t 8 boron
refined
be considered
amount of of
of
should
of
with
increasing
microstructure
in
Fig,
3). enalyses
The X-ray phase
perenegnetic
and
that
th8 addition
5 alloy
c8uses
from 2.8728 2.8752 the
g.
fact
by both
of
boron
in
the increese
These
changes
boron
constants
OC phase
of
8 to 2.8788
that
lattice
performed
of
lattice the
lattice
introduced
0.003
constants d
phase
constant
into
ferromegneticoc’
edditionelly
the amount of
fi end of of
of
of the
5 alloy
ehown Alnico
the Oc’ phase
from 2.8773
of
Alnico
have
wt% into
phases is
(z to confirm
COnt8inOd
phaees.
CONCLUSION8 results
The equal
to 0*003
advsntegeous creesing
Hc and
It
rhould
This Polish
Alnico
the point
(6H)max with
be also of
of
by u*
the alloy noted
that
(facilitates
work has been Academy of
equiaxial of the
free
addition
the addition
subsidized Warsaw,
by the
of
by ca.
element. of
boron rise
grein)
to 0.003 both
and of
Institute
of
wt
to
nicro-
7 phase).
Poland.
is in-
end
induction
5 8110~ giving of
structure
% reapectively this
(refinement
boron
properties,
remanent
from
of
grain
msgnetic
10 % and li
precipitation
Science,
the
view
of Alnico
macroetructure
that
5 of
decreasing
the properties
the changes structure
wt% into
slightly
1 % as Compared
4; effects
have
from
riaultaneouely
shown
obtained
Physics,
495
REFERENCES 1 2 3
S. szymura and 6. WyeZocki, Elektronlka, a (1980) 14. K. SchOler, TEW- Technieche Berlchte, 2 (1977) 41. L.
So ka and 33.
S.
Prace
Szymura,
Inetvtut6w
Hutnlczvch,
29
( cmj
4 6 6 7
Yu.A. Gracyanov, B.H. Putlmcev, B.V. Molotilov. V.P. Gvcharov and V.I. Krasnych , Mstallurava Precizvonnvch Bplavov, Metallurgya , Moscow, 19% . P. 283 . V.V. sergeyeva and T.I. Bulyglna, Maanltotvlorch Materlalv 0 Energya, MOSCOW, 1980. Pa 139. L, Sojka and A. Zawada, Mat. scl.0 2 (1979) 43. S. Srynura, s. szymura and S. Golba, 3. Maan. Mann. Mat., 24 (1981) 285.
8
S.
Szymura,
3.
Mean.
Mean.
Mat.,
30
(1983)
389.
g
S.
szymura,
3.
Maan.
Mean.
Mat.,
37
(1983)
69.
10
S.
Szymura,
Acta
Maan.,
11 12
S. Srymura, S. stynura,
Acta
Mean.,
Wladono6cl
2 (1986). 2 (1985) . Hutnlcte,
NO* 2-3
(1970)
70.
Chemistry
and Physics,
13 (1985)
489-495
489
SHORT COMMUNICATION
THE EFFECT OF BORON ON THE MAGNETIC
OF AlNlCo
PROPERTIES
5
PERMANENT MACWET ALLOYS
s.
SZYMURA
Institute of Phyeics, 42-200 CrQstochowa
Technics1
of Ferrous
Metallurgy,
Institute Received
March
20
1985;
University,
Zewadrkiego
Gliwice
44-100
accepted
Al.
22 April
(Poland
19,
)
1985
ABSTRACT The Investigation of the effect of boron (0 - 1.0 wt%) on the magnetic properties of magnetically hard Alnlco 5 allo of equiaxial grain structure has shown that the addition of t Kla element in the amount up to 0.003 wt% Increases the coercive force end maxlmua magnatic ener y product but decreases tha renenant induction. Tha addition o 3 boron * 0.003 wt% causes the decrease of those
properties
INTRODUCTION NotwIthstanding
[ 11,
Alnlco
netariala
the
type for
applicatlone Alnico
type
tically the
logical also riala.
materlela
magnetic
an important
magnets
used
are
alloys
the
group
In various
of
technical
of
magnetic
practice
theory
composition
properties
the in
basic
aateriala
properties
far
are
in
and have
of
from those
the theorb
[I]. of
alloying
elements
common waye
moat
propertlaa
to improve
A ayetemetited
02%0584/85/$3.30
renagnetiratlon the
on magnetic
obtelned
and physlcal applied
concerning
Nevartheleaa
introduction
melt
of
In addition,
influence
predicted
Tha
solved
alloys.
aetabillahed.
Alnico
new hard
conetltute
production are
type
heat-treatment been
still
of
[ 2,3].
Many problems the
alloys
the
appearance
of
functional analysis
used
and
for
aetala.
their
addition
laproving
the
An Identical
qualities of
tha
influence
of
aethod
aagnetic of
0 Elsevier Sequoia/Printed
into
techno-
certain
la
mataale-
in The Netherlands
490
ments on magnetic alloys data
properties of
the eddition
permanent
of
of
The purpose
properties
of
magnetically
herd
type were published
on the effects
those of
snd mechanical
of Alnico
[ 5,6], and recently 808% new S, Nb, Hn, Cs-miech@etel end Se on
Ti.
the
Alnico
the present
of
ragnst
boron
llloy
5
work is
were discussed
(7-101.
to Investigate
on the nagnetic
properti%s
the effect of Alnlco
5
efloys.
EXPERIMENTAL Material The chemical
of
conpoeltion
-25Ni-24Co-3Cu-x8
with
OS
means of % vacuum induction diameter.
of
25 nin
rat% which
was 8ufficiently
phbSe,
since
this
tic
propertlse
of
a magnetic
fibld
which
was 8llOWed
the
was ennealsd
method
of
in
were
melted
cylinder
of
effect
Intensity,
OCCUr8 , was oarrfed fisld
by
15 mm
by heating
910 K for
4 hrs
8t
a
of
ths
cooling
(15 K*nin-‘)
during
which decon-
out
was again
et
on ths nagne-
from 1$70 to 8M
removed
and cooling
down to room temperature.
freely
at
out
prseipitation
. Controlled
(ii]
magnetic
and at 830 K for
Then the 15 hre.
applied method8 of prOperti68
M8t8llographlc
StUdi
invebtigstion and of
by a norms1 metallographic
cture
of
propertIe
type AEG p%rmeamoter with treatm%nt surface
oxidized
on poll8hed Macro-
by the method given
were determin8d tha accurecy
the epocimens
the me8surem8nt8
8nd niorOstructUrer
t8ChniqUe.
88mples were reveslsd
The magnstlc
covered
tha macro-
wer8 p8rfOrm8d
parsd
ence of
was (Sl-x)Fe-8Al
(5 K*%ec-I)
to prevent
240 kA*n*’
th8 nagnbtic
heat
end ca8t
by cooling
high
the alloy
to proceed
The applied of
elloye
The alloys
phase has a detrimental
pO8&tiOn Of the oLph88e
Teat
furnace
and was followed
In
alloy
wt%.
the apeclmene was carried
1520 K for
K, aft8r
tested
The boron was sdded es ferro-boron.
Homogenization
r
the
x G 1.0
were
layer8
of
ground
seCtlOn8 1121,
in
by me8ne of the order
to ellafnate
on the magnetic
pre-
%nd nicrostru8 MJ-55
1%. After
the
influ-
propertiee.
RESULTS AND DISCUSSION The dependence of and mexlmun magnetic
loy
of
equiaxiel
grain
coercfve energy
force product
structure
(He),
remanent induction
((SH)max)
in
the Alnlco
on the proportion%1
content
i Srf 5 alof
L"O
2.1f3
10-2
1o4 B [wt %I
t Fig. 1. Influence of boron residual induction ( (BH)max ).
(Bf)
boron
in
Is
sented
presented
It
is
apparent
and
addition magnetic
force ( tic) , product
on the coercive maximum energy
Fig.
1. From the
that
the
shape
character
of
and
the
range
curves of
pre-
the
changes
magnetic properties are significantly dependent on the boron in the alloy. The addition of boron up to 0.003 wt% inc-
of
content reases ie
both
more
product.
For
decrease. sted
boron
The
range
The
Hc and
pronounced
of
observed
re
of
additions
of
Induction of
changes
Increase
x a
the
of
the
coercive
maximum magnetic
0.003
wt% both
decreases
within
force energy
Hc and
(BH) max
whole te-
the
boron.
of
magnetic
structure with
the with
remanent
be connected the
and
compared
addition
of equiaxial grain should
(BH)nax as
the
properties
resulting changes
alloy because, as Is seen
from
of the
of
macro-
from
our
Alnico
addition and
results
alloy
5 of
boron
micro-structu(see
Figs
2
Fig. with
2. Hacroatructure boron additions,
of (b)
Alnico 0.0051
5 alloy without boron wt%, (c) 1.0 wt%
(a),
and
493
Fig. with
3 W&crostructure bot’on additions,
of Alnico (bf 0,003
5 alloy without wt%, (c) 0.0038
boron (a), and wt%, Id] 0.015 wt%
494
and 3). 8lloY
these grain
appeared
Size
also
chengee
negligibly
wt% but
the grains
x==0.003
rut% (see
finenent
of
qI8gnetiC
induction
decreesee
magnetic
induction
flux
tization
direction.
also
caused
phese
are
due to the addition
strongly
examples
grains
on grain
a” phase
preeent
the
content;
at
boron
T phase
addition
is
of
of
the magnetic
small
boron
of
non-magnetic
its
8bOVO 0.003
of
losses
of
to the aagne-
properties
the alloy
is
~~0.003
The
depends
on
wt% the amount
increases
wt% (compare
7
[i2].
significantly
Content
fraction
The re-
causes
high-temperature
of
the alloy
the boron but
normal
content 2).
the the
the aegnetic
properties in
due to
boundaries
The decrease
of
The
~~~0.003
boron
in Fig.
es one
the alloy
boron.
Content
when the
macroetructufes of
by the presence
worsening
8t 8 boron
refined
be considered
amount of of
of
should
of
with
increasing
microstructure
in
Fig,
3). enalyses
The X-ray phase
perenegnetic
and
that
th8 addition
5 alloy
c8uses
from 2.8728 2.8752 the
g.
fact
by both
of
boron
in
the increese
These
changes
boron
constants
OC phase
of
8 to 2.8788
that
lattice
performed
of
lattice the
lattice
introduced
0.003
constants d
phase
constant
into
ferromegneticoc’
edditionelly
the amount of
fi end of of
of
of the
5 alloy
ehown Alnico
the Oc’ phase
from 2.8773
of
Alnico
have
wt% into
phases is
(z to confirm
COnt8inOd
phaees.
CONCLUSION8 results
The equal
to 0*003
advsntegeous creesing
Hc and
It
rhould
This Polish
Alnico
the point
(6H)max with
be also of
of
by u*
the alloy noted
that
(facilitates
work has been Academy of
equiaxial of the
free
addition
the addition
subsidized Warsaw,
by the
of
by ca.
element. of
boron rise
grein)
to 0.003 both
and of
Institute
of
wt
to
nicro-
7 phase).
Poland.
is in-
end
induction
5 8110~ giving of
structure
% reapectively this
(refinement
boron
properties,
remanent
from
of
grain
msgnetic
10 % and li
precipitation
Science,
the
view
of Alnico
macroetructure
that
5 of
decreasing
the properties
the changes structure
wt% into
slightly
1 % as Compared
4; effects
have
from
riaultaneouely
shown
obtained
Physics,
495
REFERENCES 1 2 3
S. szymura and 6. WyeZocki, Elektronlka, a (1980) 14. K. SchOler, TEW- Technieche Berlchte, 2 (1977) 41. L.
So ka and 33.
S.
Prace
Szymura,
Inetvtut6w
Hutnlczvch,
29
( cmj
4 6 6 7
Yu.A. Gracyanov, B.H. Putlmcev, B.V. Molotilov. V.P. Gvcharov and V.I. Krasnych , Mstallurava Precizvonnvch Bplavov, Metallurgya , Moscow, 19% . P. 283 . V.V. sergeyeva and T.I. Bulyglna, Maanltotvlorch Materlalv 0 Energya, MOSCOW, 1980. Pa 139. L, Sojka and A. Zawada, Mat. scl.0 2 (1979) 43. S. Srynura, s. szymura and S. Golba, 3. Maan. Mann. Mat., 24 (1981) 285.
8
S.
Szymura,
3.
Mean.
Mean.
Mat.,
30
(1983)
389.
g
S.
szymura,
3.
Maan.
Mean.
Mat.,
37
(1983)
69.
10
S.
Szymura,
Acta
Maan.,
11 12
S. Srymura, S. stynura,
Acta
Mean.,
Wladono6cl
2 (1986). 2 (1985) . Hutnlcte,
NO* 2-3
(1970)
70.