Cast AlNiCo Magnets

Cast AlNiCo magnets are made of liquid AlNiCo by melting an alloy of aluminum, nickel and cobalt at very high temperatures (1400-1500 degrees Celsius) and then under very high pressures (500-1000 tons per square centimeter), when it has cooled sufficiently, the resulting cast Alnico block can be drilled, sawed, ground or turned on a lathe according to specific requirements. Cast AlNiCo magnets usually require heat treatment to further improve their coercivity properties. Cast AlNiCo magnets are divided into isotropic and anisotropic forms according to the direction of application of the magnetic field to orient the magnet after heat treatment; if no magnetic field is applied during cooling, it can be classified as an isotropic material; Instead, if they were cooled with a magnetic field applied, it would become an anisotropic material.

Alnico magnet pdf
Cast AlNiCo magnets are used in many applications including electric motors, instruments, speakers and more. According to customers’ special drawings or specifications, different cast AlNiCo magnet structures are required. Cast AlNiCo magnet plays an important role in modern industry for its excellent magnetic properties, high strength and hardness. Cast Alnico magnets are typically manufactured by conventional casting processes at 2100°C using conventional casting equipment.
 
Cast AlNiCo magnets can be processed into different sizes and shapes, with better machinability and strong plasticity; among permanent magnet materials, Cast AlNiCo magnets have the lowest reversible temperature coefficient, and the working temperature can be as high as 500 degrees Celsius . Most Alnico magnets are cast type. The most common Alnico Cast magnets are grades 2, 3, 4, 5, 6, 8 and 9. They retain about 85% of their room temperature strength at temperatures up to 550°C. They are completely demagnetized at about 850°C. For best results with Alnico 5 magnets, the length should be no less than 5 times the cross-sectional diameter or the diameter of a circle equal to the cross-sectional area.

Performance table of Cast alnico magnet

grade remanence

Br

 COERCIVE FORCE
Hcb		 MAXIMUM ENERGY PRODUCT
(BH)max		 curve temperature HIGHEST WORKING TEMPERATURE Domestic grade
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