Sintered AlNiCo Magnet

AlNiCo magnets emerge from either a sintering or casting process, with casting being the more common method, each tailored to specific industrial needs. A sintered AlNiCo magnet is crafted by pressing fine metallic powder into a die shaped nearly to its final form, then heating it to fuse into a solid structure. Though its magnetic performance trails slightly behind that of cast AlNiCo magnets, the sintered AlNiCo magnet suits small-to-medium designs, typically under 28 grams, including thin, lightweight, or specially shaped components ideal for precision applications.

The sintered AlNiCo magnet offers distinct advantages, such as exceptional dimensional accuracy that removes the need for further machining. It also provides superior mechanical strength and easier machinability compared to cast counterparts. In large-scale production, sintered AlNiCo magnets ensure higher material utilization ratio, minimizing composition segregation and stabilizing magnetic output, resulting in reliable, high-quality products across batches.

AlNiCo magnets boast diverse trade names for their grades, such as Columax, Alcomax, Hycomax, and Ticonal, highlighting their specialized uses. The sintered AlNiCo magnet is commonly identified by MMPA class names like Alnico 2, 3, 5, 5DG, 8, 8HC, and 9, each reflecting unique compositions suited for varied magnetic applications.

A sintered AlNiCo magnet varies in Cobalt content, spanning from zero in Alnico 3 to 40% in Alnico 8. Lower grades (2, 3, 4), being isotropic and unoriented, deliver modest magnetic output. In contrast, anisotropic grades (5, 6, 8, 9) are engineered for strong magnetic performance in a designated direction, enhancing efficiency.

In China’s naming system, a sintered AlNiCo magnet begins with FLNG or FLNGT, followed by a number denoting the minimum maximum energy product (BH)max in kJ/m³. FLNGT stands for sintered powder, Aluminum, Nickel, Cobalt, and Titanium in Chinese phonetics, with a “J” suffix indicating high coercivity.