Alnico permanent magnet materials are generally divided into cast Alnico and sintered Alnico according to the manufacturing process. Sintered Alnico magnets adopt the pressing-sintering process, and their metal yield can reach over 95%. Compared with cast Alnico materials, sintered Alnico magnets have high mechanical properties and are suitable for environments with high vibration and shock due to their fine grain size and lack of casting defects, and can be manufactured into various shapes by powder pressing, which are widely used in various small devices. Cast Alnico is usually used for larger devices with higher performance than sintered Alnico, and some very small devices that require wire-cutting are also commonly used in cast Alnico.