Introduction:
AlNiCo is the earliest developed permanent magnet material, which is an alloy composed of aluminum, nickel, cobalt, iron, and other trace metal elements. AlNiCo permanent magnet materials were successfully developed in the 1930s. At that time, it had the best magnetic performance and small temperature coefficient, so it was most widely used in permanent magnet motors. After the 1960s, with the successive advent of ferrite permanent magnets and rare earth permanent magnets, the application of AlNiCo permanent magnets in motors was gradually replaced, and the proportion showed a downward trend.
Permanent Magnet AlNiCo is an iron alloy, in addition to iron, aluminum, nickel, cobalt, and small amounts of other components that enhance magnetic properties are added.
AlNiCo alloys have a high coercivity and high Curie temperature. AlNiCo alloys are hard and brittle, cannot be cold worked, and must be processed by casting or sintering procedures. AlNiCo can generate magnetic fields as high as 0.15 Tesla. As an example of an anisotropic cast AlNiCo alloy with intermediate properties, Alnico-6 is composed of 8% Al, 16% Ni, 24% Co, 3% Cu, 1% Ti, and the rest are Fe. The maximum energy product (BHmax) of Alnico-6 is 3.9 megagauss-oersteds (MG Oe), the coercivity is 780 oersted, the Curie temperature is 860 °C, and the maximum operating temperature is 525 °C.
Types:
According to different production processes, it is divided into sintered AlNiCo and cast AlNiCo. The shapes of the products are mostly round and square. The casting process can be processed into different sizes and shapes; compared with the casting process, the sintered product is limited to small sizes, and the dimensional tolerance of the blank produced is better than that of the cast product blank, and the magnetic properties are slightly lower than the cast product, but can be Processability is better. Among permanent magnet materials, cast AlNiCo permanent magnets have the lowest reversible temperature coefficient, and the working temperature can be as high as 600 degrees Celsius. AlNiCo permanent magnet products are widely used in various instrumentation and other application fields.
Applications:
Many industrial and consumer products require strong permanent magnets, such as electric motors, electric guitar pickups, microphones, sensors, speakers, traveling wave tubes, cattle magnets, etc., all use Alnico magnets. But now, many products are switching to rare earth magnets, because these materials can give a stronger magnetic field and a higher maximum magnetic energy product, allowing the product to be reduced in size.
