Alnico Magnets By Star Trace Pvt. Ltd.

Alnico magnets are made primarily from aluminum, nickel,cobalt, copper, iron and sometimes titanium. They can be either cast or sintered.
Cast Alnico
Cast Alnico melted and poured into a mold. Once solidified, the material is rough ground and then heat-treated and cooled, sometimes in a magnetic field. When treated in the presence of a magnetic field, The magnet is called anisotropic. This orients the material to take on maximum magnetization and allows a higher gauss level. A cast magnet that is not heat-treated in a magnetic field is called Isotropic. After heat treatment and cooling, the material can be ground to specific tolerances and then magnetized.
Sintered Alnico
Sintered alnico is made from a powdered mixture of ingredients that are pressed into a die under tons of pressure, sintered in a hydrogen atmosphere and then cooled either within a magnetic field or without (anisotropic Vs Isotropic).
Attributes of both Cast and Sintered Alnico

* Very temperature stable, great for high heat applications.
* Maximum working temperature 525OC - 550OC
* May be ground to size
* Does not lend itself to conventional machining (Hard and Brittle)
* High residual induction and energy product compared to Ferrite material
* Low coercive force compared to Ferrite and rare earth materials (more subject to demagnetization)
* Most common grades of Alnico are 5 and 8