Cast AlNiCo Magnet

The Cast alnico magnet is made through melting an alloy of aluminum, nickel and cobalt at very high temperatures (1400-1500 degrees Celsius) to form liquid alnico which is then poured into the mounds under very high pressure (500-1000 tons per square centimeter). When it has cooled down enough, the resulting block of cast alnico can be drilled, sawed, ground or turned-on lathes depending on specific requirements. Cast AlNiCo magnet often requires heat treatment to further raise their coercivity performance. The Cast AlNiCo magnet is divided into isotropic form and anisotropic form depending on the applying direction of the magnetic field to orient magnets after heat treatment; it can be classified as isotropic material if they do not apply magnetic field during cooling process; instead, it will become anisotropic material if they apply magnetic field during cooling process.

Cast AlNiCo magnets can be used in many applications including motors, instruments, loudspeakers, etc. Different Cast AlNiCo Magnet structures are required according to customer’s special drawing or specification. Cast AlNiCo plays an important part in modern industry due to their excellent magnetic properties, high strength and hardness. Cast AlNiCo magnet is often manufactured by conventional foundry processes using conventional foundry equipment at 2100℃.

Cast AlNiCo Magnet can be processed into different sizes and shapes, with better machinability and strong plasticity; among the permanent magnet materials, cast AlNiCo magnets have the lowest reversible temperature coefficient, and the working temperature can be as high as 500 degrees Celsius. The majority part of AlNiCo magnets is cast type. The most common Alnico cast magnets are in grades 2, 3, 4, 5, 6, 8, and 9. They maintain approximately 85% of their room-temperature strength up to 550℃. They become completely demagnetized at approximately 850℃. For best results with Alnico 5 magnets, the length should be no less than 5 times the cross-section diameter or the diameter of a circle equal in area to the cross-section.

 

Magneitc Properties of Cast ALnico Magnet

Grade RemanenceBr CoercivityHcb
Hcb Max. Energy Product
(BH)max Curie Temp. Max. Operating Temperature MMPA Equivalent
mT Gs kA/m Oe kJ/m3 MGOe ℃ ℃
LN10
600
6000
40
500
10
1.2
750
550
AlNiCo3
LNG12
700
7000
44
550
12
1.5
750
550
AlNiCo2
LNG13
680
6800
48
600
13
1.63
800~850
550
LNG18
900
9000
48
600
18
2.25
800~850
550
AlNiCo4
LNG37
1200
12000
48
600
37
4.63
800~850
550
AlNiCo5
LNG40
1250
12500
48
600
40
5
800~850
550
LNG44
1250
12500
52
650
44
5.5
800~850
550
LNG52
1300
13000
56
700
52
6.5
800~850
550
AlNiCo5DG
LNG56
1300
13000
58
720
56
7
800~850
550
 
LNG60
1330
13300
60
750
60
7.5
800~850
550
AlNiCo5-7
LNGT18
580
5800
90
1130
18
2.25
800~850
550
AlNiCo7
LNGT28
1000
10000
56
700
28
3.5
800~850
550
AlNiCo6
LNGT30
1100
11000
56
700
30
3.75
800~850
550
AlNiCo6
LNGT32
800
8000
100
1250
32
4
800~850
550
AlNiCo8
LNGT38
800
8000
110
1380
38
4.75
800~850
550
LNGT44
850
8500
120
1500
44
5.5
800~850
550
LNGT48
900
9000
120
1500
48
6
800~850
550
LNGT60
950
9500
110
1380
60
7.5
800~850
550
LNGT72
1050
10500
112
1500
72
9
800~850
550
AlNiCo9
LNGT88
1100
11000
115
1450
88
11
800~850
550
LNGT96
1150
11500
118
1480
96
12
800~850
550
LNGT36J
700
7000
140
1750
36
4.5
800~850
550
AlNiCo8HC
LNGT48J
800
8000
145
1820
48
6
800~850
550
AlNiCo8HC
LNGT52J
850
8500
140
1750
52
6.5
800~850
550
AlNiCo8HC