Alnico
materials (composed predominantly of aluminum,nickel,and cobalt
with minor amounts of other elements including titanium and copper)
permit design latitudes providing high indications,high energies
and relatively high coercivities.Alnico magnets are characterized
by excellent temperature stability and good resistance to demagnetization
from vibration and shock.Alnico magnets offer the best temperature
characteristics of any standard production magnet material available,.They
can be used for continuous duty applications where temperature extremes
up to 930F can be expected.
Alnico magnetsl are
manufactured through either a casting or sintering process. Alnico
magnet is very hard and brittle.Machining or drilling can not therefore
be accomplished by ordinary methods.Holes are usually cored in at
the foundry.Magnets are cast or sintered as closely as possible
to required sized so that abrasive grinding to finish dimensions
and tolerances is minimized
Specialized
casting techniques used to achieve
the unique crystalline grain orientation found in the Alnico 5 and
8 grades.These anisotropic grades are designed to produce high magnetic output in a specified
direction.Orientation is achieved during heat treatment, by cooling
the casting
from 2000F at a controlled
rate within a magnetic field which conforms to the preferred direction
of magnetization. Alnico 5 and Alnico 8 are anisotropic and exhibit a preferred
direction of orientation,Magnetic orientation should be specified
on your drawing when you send an order to us.
Cast
Alnico 5
is the most commonly used of all the cast Alnico's .It combines
high indications with a high energy product of 5 MGOe or more and
is used extensively in rotation machinery, communications, meters
and instruments, sensing devices and holding applications. The higher
resistance to demagnetization(coercive force) of Alnico 8,cobalt content to 35%,allows this material to function well
for short lengths or for length to diameter ratios of less than
2 to 1.
Sintered
Alnico materials offer slightly lower magnetic properties but butter mechanical characteristics
than the cast Alnico materials.Sintered Alnico magnets are most suitable
in small sizes(less than 1 oz.)in this process. The desired mix
of metal powder is pressed to shape and size in a die,then sintered
at 2300 F in a hydrogen atmosphere.The sintering process is well
suited to large volume production,and results in parts which are
structurally stronger than cast magnets.Relatively close tolerances
can be achieved without grinding.
The
Characteristics of Alnico Magnet:
*Small changes in
magnetic properties to temperature effects
*Maximum working temperature
can be as high as 450oC~550oC.
*Low coercive force.
*Strong corrosion
resistance capability,no coating needed for surface protection.
Typical Applications
for Alnico magnet:
Widely used applications
such as instruments and meters which require very stable
temperature properties.
Electronic ignition
systems,watt bour meters,volt-amp meters.medical instruments,industrial
motors,magnetic reed switches,generators,hand tools,vending machines.
Typical
Magnetic Performance Range for Cast Alnico Magnet
Grade
|
Br
|
Hc
|
(BH)max
|
MMPA Equivalent
|
Temp. Coefficient
|
Tc
|
Tw
|
mT
|
KGs
|
KA/M
|
Oe
|
KJ/m3
|
MGOe
|
%/
|
|
|
LN9
|
690
|
6.9
|
37
|
470
|
10.0
|
1.25
|
Alnico1
|
-0.03
|
760
|
500
|
LNG12
|
700
|
7
|
40
|
500
|
12.0
|
1.50
|
Alnico2
|
-0.03
|
810
|
500
|
*LNG13
|
680
|
6.8
|
48
|
600
|
12.0
|
1.50
|
Alnico2
|
-0.03
|
810
|
500
|
*LN10
|
600
|
6
|
40
|
500
|
10
|
1.2
|
Alnico3
|
-0.03
|
760
|
500
|
LNGT18
|
580
|
5.8
|
90
|
1130
|
18.0
|
2.20
|
[l.Alnico7]
|
-0.03
|
860
|
500
|
LNG16
|
800
|
8
|
53
|
660
|
16.0
|
2.00
|
[Alnico4]
|
-0.02
|
850
|
500
|
LNG34
|
1180
|
11.8
|
44
|
550
|
35.0
|
4.30
|
[Alnico5C]
|
-0.02
|
890
|
500
|
LNG37
|
1180
|
11.8
|
48
|
600
|
37.0
|
4.65
|
Alnico 5
|
-0.02
|
890
|
500
|
LNG40
|
1220
|
12.2
|
48
|
600
|
40.0
|
5.00
|
-0.02
|
890
|
500
|
LNG44
|
1220
|
12.2
|
52
|
650
|
44.0
|
5.50
|
Alnico 5 DG
|
-0.02
|
890
|
500
|
LNG 52
|
1250
|
12.5
|
55
|
690
|
52.0
|
6.50
|
Alnico 5-7
|
-0.02
|
890
|
550
|
LNG60
|
1300
|
13
|
56
|
700
|
60.0
|
7.50
|
Alnico 6
|
-0.02
|
890
|
500
|
LNGT28
|
1050
|
10.50
|
56
|
700
|
28.0
|
3.50
|
Alnico 8
|
-0.02
|
860
|
550
|
LNGT32
|
800
|
8
|
104
|
1300
|
34
|
4.25
|
-0.03
|
860
|
550
|
LNGT38
|
820
|
8.2
|
110
|
1380
|
38.0
|
4.75
|
-0.03
|
860
|
550
|
LNGT44
|
880
|
8.8
|
120
|
1500
|
44.0
|
5.50
|
-0.03
|
860
|
550
|
LNGT60
|
900
|
9
|
110
|
1380
|
60
|
7.5
|
Alnico 9
|
-0.03
|
860
|
550
|
LNGT72
|
1050
|
10.5
|
112
|
1410
|
72
|
9
|
|
-0.03
|
860
|
550
|
LNGT36J
|
700
|
7
|
140
|
1750
|
36
|
4.5
|
Alnico 8HC
|
-0.03
|
860
|
550
|
Demagnetization Curve of Cast Alnico
Magnet
l Inspection standard
for permanent magnet
l Purchasing Guide
l Permanent magnet
supply direction
l Surface protection
and surface coating for the permanent magnet
l Quality warranty
l Safety principle
for manual operation of permanent magnet
|