Cast AlNiCo Magnet
The Cast alnico magnet is made through melting an alloy of aluminum, nickel and cobalt at very high temperatures (1400-1500 degrees Celsius) to form liquid alnico which is then poured into the mounds under very high pressure (500-1000 tons per square centimeter). When it has cooled down enough, the resulting block of cast alnico can be drilled, sawed, ground or turned-on lathes depending on specific requirements. Cast AlNiCo magnet often requires heat treatment to further raise their coercivity performance. The Cast AlNiCo magnet is divided into isotropic form and anisotropic form depending on the applying direction of the magnetic field to orient magnets after heat treatment; it can be classified as isotropic material if they do not apply magnetic field during cooling process; instead, it will become anisotropic material if they apply magnetic field during cooling process.
Cast AlNiCo magnets can be used in many applications including motors, instruments, loudspeakers, etc. Different Cast AlNiCo Magnet structures are required according to customer’s special drawing or specification. Cast AlNiCo plays an important part in modern industry due to their excellent magnetic properties, high strength and hardness. Cast AlNiCo magnet is often manufactured by conventional foundry processes using conventional foundry equipment at 2100℃.
Cast AlNiCo Magnet can be processed into different sizes and shapes, with better machinability and strong plasticity; among the permanent magnet materials, cast AlNiCo magnets have the lowest reversible temperature coefficient, and the working temperature can be as high as 500 degrees Celsius. The majority part of AlNiCo magnets is cast type. The most common Alnico cast magnets are in grades 2, 3, 4, 5, 6, 8, and 9. They maintain approximately 85% of their room-temperature strength up to 550℃. They become completely demagnetized at approximately 850℃. For best results with Alnico 5 magnets, the length should be no less than 5 times the cross-section diameter or the diameter of a circle equal in area to the cross-section.