Sintered AlNiCo manget

Sintered Alnico magnets are formed by compacting fine Alnico powder in a press and then sintering the compacted powder into a solid magnet. The powdered mixture of contents is pressed into a die under tons of pressure. It is then sintered in a hydrogen atmosphere at 2300F and then cooled - either within a magnetic field or without a magnetic field. When cooled within the magnetic field it is known as an anisotropic magnet and when cooled outside of a magnetic field it is called an isotropic magnet. The sintering process is well suited to large volume production.

sintered alnico

Sintered alnico magnets have lower magnetic properties than cast magnets but better mechanical properties. They are most suitable for small sizes that are less than 1 oz. It also results in parts that are structurally stronger than the cast alnico magnets. With the sintering process, one can achieve relatively close tolerances without any grinding.

Raw materialPowderFormingSmeltingPackingPrecision grindnig

Surface treatmentHeat treatmentFinal inspectionStecking

Characteristics:

  • High mechanical strength, suitable for small volume magnets with complex shape.
  • Fine crystalline metallic structure;
  • Good corrosion resistance;
  • Suitable for compound magnet
  • Excellent temperature stability (temp. coefficient of Br is the smallest among all of the other permanent magnets)

sinter alnicosinter alnico

Applications:

  • Inner magnetic voltmeter/ammeter, electronic type power energy measuring instrument, avometer and flow meter ect;
  • A wide range of magnetic sensor, polarized relay, temperature/ pressure controller
  • Buzzer or mobile phone, hearing aids, mini speaker.
  • Lighter of automobile, odometer of automobile and motorcycle, permanent motor, adsorptive appliance.
  • Widely applied in high stability fields as aviation, spaceflight and military technology.

Typical Magnetic Performance Range for Sintered Alnico

Grade Br Hc (BH)max Tc Tw Temp. Coefficient
a(Br)
MMPA Equivalent Remark
mT KGs KA/m Oe KJ/m3 MGOe %/℃
FLN8 550 5.5 42 530 9.0 1.13 760 450 -0.022 [S.Alnico3] Isotropic
FLNG12 700 7 48 600 12.4 1.55 810 450 -0.014 [S.Alnico2]
FLNGT18 580 5.8 90 1130 18.0 2.20 860 450 -0.020 [S.Alnico7]
FLNG34 1100 11 48 600 34.0 4.25 890 450 -0.016 S.Alnico5 Anisotropic
FLNGT28 1000 10 56 700 28.0 3.50 850 450 -0.020 S.Alnico6
FLNGT38 800 8 120 1500 38.0 4.75 850 450 -0.020 S.Alnico8
FLNGT42 850 8.5 120 1500 42 5.25 820 450 -0.020
FLNG33J 680 6.8 140 1750 33.0 4.13 850 450 -0.025 S.Alnico8HC
sintered alnico alloy

Demagnetization Curve of Sintered AlNiCo Permanent Alloy

Sintered AlNiCo Demagnetization Curve