Catégories
Matériau aimant Alnico

Matériau aimant Alnico



Description

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 magnets 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.


Avantage concurrentiel:
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.

• Suitable for small volume magnets with complex shape
• Compact crystal, high intensity
• Regular shape, precision size
• Even elements, stable performance
• Suitable for compound magnet
• Excellent temperature stability (temp. coefficient of Br is the smallest among all of the other permanent magnets

Spécifications

Magnetic and Physical Properties of Cast Alnico Magnet

Grade Equivalent MMPA Class Rémanence force coercitive Maximum Energy Product Densité Reversible Temp. Coefficient Reversible Temp. Coefficient Temp Curie. Temp. Coefficient Remarque
Br Hcb (BH) max g / cm3 α(Br) α(Hcj) TC TW
mT Gs KA / m Oe KJ / m3 MGOe % / ℃ % / ℃
LN10 ALNICO3 600 6000 40 500 10 1.2 6.9 -0.03 -0.02 810 450 Isotropy
LNG13 ALNICO2 700 7000 48 600 12.8 1.6 7.2 -0.03 +0.02 810 450
LNGT18 ALNICO8 580 5800 100 1250 18 2.2 7.3 -0.025 +0.02 860 550
LNG37 ALNICO5 1200 12000 48 600 37 4.65 7.3 -0.02 +0.02 850 525 Anisotropy
LNG40 ALNICO5 1250 12500 48 600 40 5 7.3 -0.02 +0.02 850 525
LNG44 ALNICO5 1250 12500 52 650 44 5.5 7.3 -0.02 +0.02 850 525
LNG52 ALNIC05DG 1300 13000 56 700 52 6.5 7.3 -0.02 +0.02 850 525
LNG60 ALNICO5-7 1350 13500 59 740 60 7.5 7.3 -0.02 +0.02 850 525
LNGT28 ALNICO6 1000 10000 57.6 720 28 3.5 7.3 -0.02 +0.03 850 525
LNGT36J ALNICO8HC 700 7000 140 1750 36 4.5 7.3 -0.025 +0.02 860 550
LNGT38 ALNICO8 800 8000 110 1380 38 4.75 7.3 -0.025 +0.02 860 550
LNGT40 820 8200 110 1380 40 5 7.3 -0.025 860 550
LNGT60 ALNICO9 900 9000 110 1380 60 7.5 7.3 -0.025 +0.02 860 550
LNGT72 1050 10500 112 1400 72 9 7.3 -0.025 860 550

Magnetic and Physical Properties of Sintered Alnico Magnet

grades Equivalent MMPA Class Rémanence force coercitive force coercitive Maximum Energy Product Densité Reversible Temp. Coefficient Temp Curie. Temp. Coefficient Remarque
Br Hcj Hcb (BH) max g / cm3 α(Br) TC TW
mT Gs KA / m Oe KA / m Oe KJ / m3 MGOe % / ℃
SLN8 Alnico3 520 5200 43 540 40 500 8-10 1.0-1.25 6.8 -0.02 760 450 Isotropy
SLNG12 Alnico2 700 7000 43 540 40 500 12-14 1.5-1.75 7.0 -0.014 810 450
SLNGT18 Alnico8 600 6000 107 1350 95 1200 18-22 2.25-2.75 7.2 -0.02 850 550
SLNGT28 Alnico6 1000 10000 57 710 56 700 28-30 3.5-3.8 7.2 -0.02 850 525 Anisotropy
SLNG34 Alnico5 1100 11000 51 640 50 630 34-38 3.5-4.15 7.2 -0.016 890 525
SLNGT31 Alnico8 780 7800 106 1130 104 1300 33-36 3.9-4.5 7.2 -0.02 850 550
SLNGT38 800 8000 126 1580 123 1550 38-42 4.75-5.3 7.2 -0.02 850 550
SLNGT42 880 8800 122 1530 120 1500 42-48 5.3-6.0 7.25 -0.02 850 550
SLNGT38J Alnico8HC 730 7300 163 2050 151 1900 38-40 4.75-5.0 7.2 -0.02 850 550