The composition of AlNiCo
Alnico magnetsis one of the first developed a permanent magnet material, is an alloy composed of aluminum, nickel, cobalt, iron and other trace metal elements. Alnico permanent magnet material was successfully developed in the 1930s. Before the invention of rare earth permanent magnet materials in the 1960s, aluminum-nickel-cobalt alloy has always been the strongest magnetic permanent magnet materials, but due to the composition of strategic metals cobalt and nickel, resulting in higher costs, with the advent of ferrite permanent magnet and rare earth permanent magnet, aluminum-nickel-cobalt materials in many applications gradually replaced. However, in some high-temperature applications andhigh magneticstability requirements, the magnet still occupies an unshakable position.
Alnico production process and brand
Alnico magnetshave two processes of casting and sintering, and the casting process can be processed into different sizes and shapes; Compared with the casting process, the sintered product is limited to a small size, the size tolerance of the blank produced is better than that of the cast product blank, the magnetic property is slightly lower than that of the cast product, but the machinability is better.
The production process of casting aluminum nickel cobalt is batching → melting → casting → heat treatment → performance testing → machining → inspection → packaging.
Sintered aluminum nickel cobalt is produced by powder metallurgy, the production process is batching → powder making → pressing → sintering → heat treatment → performance testing → machining → inspection → packaging.
The performance of AlNiCo
The residual magnetic flux density of this material is high, up to 1.35T, but their intrinsic coercivity is very low, usually less than 160 kA/m, its demagnetization curve is nonlinear change, and the aluminum nickel cobalt permanent magnet loop does not coincide with the demagnetization curve, so special attention should be paid to its particularity when designing and manufacturing the magnetic circuit of the device. The permanent magnet must be stabilized in advance. For an example of an intermediate anisotropic cast AlNiCo alloy, the composition of Alnico-6 is 8% Al, 16% Ni, 24% Co, 3% Cu, 1% Ti, and the rest are Fe. The Alnico-6 has a BHmax of 3.9 megagauss-oesteds (MG·Oe), a coercivity of 780 oersted, a Curie temperature of 860 °C, and a maximum operating temperature of 525 °C. According to the low coercivity of Al-Ni-Co permanent magnet material, it is strictly prohibited to contact with any ferromagnetic material during use, so as not to cause local irreversible demagnetization or distortion ofmagnetic fluxdensity distribution.
In addition, in order to strengthen its demagnetization resistance, the surface of the Alnickel-cobalt permanent magnet pole is often designed with long columns or long rods, because the alnickel-cobalt permanent magnet material has low mechanical strength, high hardness and brittleness, resulting in poor machinability, so it can not be designed as a structural part, and only a small amount of grinding or EDM can be processed, and forging and other mechanical processing can not be used. Hangzhou Magnet Power Technology Co., Ltd. has the precision grinding ability of this product, the processing accuracy can be controlled within +/-0.005 mm, and has the production and processing ability of special-shaped products, whether it is conventional products or special special-shaped products, we can provide the appropriate way and program.
Application areas of Alnico
Cast aluminum-nickel-cobalt products are mainly used in measurement, instrument magnets, automotive parts, high-end audio, military equipment and aerospace and other fields. Sintered aluminum nickel cobalt is suitable for the production of complex, light, thin, small products, mainly used in electronic communications, permanent magnet cups, magnetoelectric switches and various sensors Many industrial and consumer products need to use strong permanent magnets, such as motors, electric guitar pickups, microphones, sensor speakers, traveling wave tubes, (cowmagnet) and so on. They all use aluminum-nickel-cobalt magnets. But now, many products are changing to use rare earth magnets, because this kind of material can give a stronger Br and a higher BHmax, allowing for a smaller product volume.
Post time: Aug-15-2024
