Alnico
Download: Performance of AlNiCo Magnets
The AlNiCo magnets feature excellent temperature stability, high residual induction, and relatively high energies characterize Alnico materials, composed primarily of alloys of Aluminum, Nickel, and Cobalt. They are manufactured through either a casting or sintering process.
Key Benefits
• Excellent temperature stability up to 1,000° F - 90% of room temperature magnetization is retained up to this temperature.• High residual induction - Alnico magnets can produce powerful fields in certain configurations.
• Material does not corrode.
• Cast Alnico magnets can be produced in relatively complex shapes.
• Tooling for cast magnets is relatively low, since sand molds are generally used for the casting process.
Key Challenges
• Alnico materials have low coercivity, meaning that they are easily demagnetized.• These magnets are relatively costly since they contain both nickel and cobalt.
• Cast Alnicos often have casting pores and voids within them - which can be problematic from cosmetics point of view or because large voids may lower expected magnetic flux.
• The material is extremely hard and brittle and difficult to machine.
Quick Facts
• Density - 0.265 lbs per cubic inch• Saturation magnetizing field required - about 5kOe
• Manufacturing methods - casting (most common), or sintering.
• Shapes available - blocks, bars, discs, rings, horseshoes, etc.
• Grades available - from about 0105 to 0519. (First 2 digits represent (BH)max, and second two digits represent intrinsic coercivity and Hcj.)
• Sizes - off tool very large Alnico magnets can be cast (for example horseshoe magnets weighing 500 pounds), or small magnets sintered (for example sintered discs, 1/16" in diameter)
Surface Treatments
No special surface treatments are required for Alnico magnets since them are resistant to oxidation. They can, however, be easily plated using a variety of metals, such as nickel or chrome.1.Typical Magnetic Performance for Cast Alnico
2.Typical Magnetic Performance for Sintered Alnico
Typical Magnetic Performance for Cast Alnico
| Grade | Br | Hcj | (BH)max | US standard | IEC standard | Ger Stand | |||
| KGs | mT | Oe | KA/m | KJ/m3 | MGOe | MMPA Equivalent | IEC Equivalent | Ge | |
| LN10 | 6.5 | 650 | 530 | 42 | 10.0 | 1.20 | Alnico 3 | Alnico 9/3 | ／ |
| LNG11 | 7.2 | 720 | 480 | 37 | 11.2 | 1.40 | Alnico 1 | Alnico 8/4 | Alnico 120 |
| LNG13 | 7.0 | 700 | 620 | 50 | 13.0 | 1.60 | Alnico 2 | Alnico 12/6 | Alnico 160 |
| LNGT18 | 5.8 | 580 | 1250 | 100 | 18.0 | 2.20 | l. Alnico 8 | Alnico 17/9 | ／ |
| LNG16 | 8.0 | 800 | 660 | 53 | 16.0 | 2.00 | Alnico 4 | ／ | ／ |
| LNG34 | 11.8 | 1180 | 550 | 44 | 34.0 | 4.25 | Alnico 5C | ／ | ／ |
| LNG37 | 12.0 | 1200 | 600 | 48 | 37.0 | 4.65 | Alnico 37/5 | Alnico 500 | |
| LNG40 | 12.2 | 1220 | 630 | 50 | 40.0 | 5.00 | Alnico 5 | ／ | |
| LNG44 | 12.5 | 1250 | 650 | 52 | 44.0 | 5.50 | Alnico 44/5 | ||
| LMG52 | 13.0 | 1300 | 690 | 55 | 52.0 | 6.50 | Alnico 5DG | Alnico 52/6 | Alnico 600. |
| LNG60 | 13.3 | 1330 | 750 | 60 | 60.0 | 7.50 | Alnico 5-7 | ／ | Alnico 700 |
| LNGT28 | 10.5 | 1050 | 700 | 56 | 28.0 | 3.50 | Alnico 6 | Alnico 26/6 | Alnico 400 |
| LNGT30 | 10.5 | 1050 | 750 | 60 | 30.0 | 3.75 | ／ | ／ | |
| LNGT32 | 8.0 | 800 | 1280 | 102 | 32.0 | 4.00 | Alnico 8 | Alnico 38/11 | Alnico 350 |
| LNGT40 | 8.2 | 820 | 1400 | 112 | 40.0 | 5.00 | |||
| LNGT44 | 8.8 | 880 | 1540 | 123 | 44.0 | 5.50 | Alnico 8B | ／ | Alnico 450 |
| LNGT48A | 9.3 | 930 | 1540 | 123 | 48.0 | 6.00 | Alnico 8HE | ／ | ／ |
| LNGT48B | 8.5 | 850 | 1650 | 132 | 48.0 | 6.00 | ／ | ／ | |
| LNGT60 | 9.0 | 900 | 1380 | 110 | 60.0 | 7.50 | Alnico 60/11 | ／ | |
| LNGT72 | 10.5 | 1050 | 1410 | 112 | 72.0 | 9.00 | Alnico 9 | ／ | ／ |
| LNGT80 | 10.8 | 1080 | 1540 | 123 | 80.0 | 10.00 | ／ | ／ | |
| LNGT88 | 11.0 | 1100 | 1575 | 126 | 88.0 | 11.00 | ／ | ／ | |
| LNGT92 | 11.5 | 1150 | 1575 | 126 | 92.0 | 11.50 | ／ | ／ | |
| LNGT36J | 7.0 | 700 | 1750 | 140 | 36.0 | 4.50 | Alnico 8 HC | Alnico 36/15 | ／ |
| LNGT40J | 7.2 | 720 | 1900 | 152 | 40.0 | 5.00 | ／ | ／ | |
| LNGT44J | 8.2 | 820 | 1800 | 144 | 44.0 | 5.50 | Alnico 4415 | ／ | |
Typical Magnetic Performance for Sintered Alnico
| Grade | Br | Hcb | Hcj | (BH)max | Density | Remark | ||||
| KGs | mT | Oe | KA/m | Oe | KA/m | KJ/m3 | MGOe | g/cm3 | ||
| FLN8 | 5.2 | 520 | 500 | 40 | 540 | 43 | 8-10 | 1.00-1.25 | 6.80 | Isotropic |
| FLNG12 | 7.0 | 700 | 500 | 40 | 540 | 43 | 12-14 | 1.50-1.75 | 6.90 | |
| FLNG14 | 5.7 | 570 | 950 | 76 | 980 | 78 | 14-16 | 1.75-2.00 | 6.90 | |
| FLNG18 | 5.6 | 560 | 1100 | 88 | 1130 | 90 | 18-22 | 2.25-2.75 | 7.00 | |
| FLNG28 | 10.5 | 1050 | 580 | 46 | 590 | 47 | 28-33 | 3.50-4.15 | 7.30 | Anisotropic |
| FLNG34 | 11.0 | 1100 | 600 | 48 | 630 | 50 | 33-38 | 4.10-4.70 | 7.30 | |
| FLNG35 | 12.2 | 1220 | 630 | 50 | 640 | 51 | 35-39 | 4.40-4.90 | 7.30 | |
| FLNGT28 | 10.0 | 1000 | 700 | 56 | 710 | 57 | 28-30 | 3.50-3.80 | 7.30 | |
| FLNGT31 | 7.8 | 780 | 1300 | 104 | 1130 | 106 | 33-26 | 3.90-4.50 | 7.30 | |
| FLNGT38 | 8.0 | 800 | 1550 | 123 | 1580 | 126 | 38-42 | 4.75-5.30 | 7.30 | |
| FLNGT42 | 8.8 | 880 | 1500 | 120 | 1530 | 122 | 42-44 | 5.30-5.50 | 7.30 | |
| FLNGT44 | 9.0 | 900 | 1500 | 120 | 1560 | 125 | 44-48 | 5.50-6.00 | 7.30 | |
| FLNG33J | 6.5 | 650 | 1700 | 136 | 1880 | 150 | 31-36 | 4.10-4.50 | 7.30 | |
| FLNGT40J | 8.0 | 800 | 1800 | 1440 | 1950 | 155 | 40-44 | 5.00-5.50 | 7.30 | |
| FLNGT44J | 8.2 | 820 | 1900 | 1520 | 2000 | 160 | 44-48 | 5.50-6.00 | 7.30 | |
