Infrared guided technology is a military technology which utilizes infrared tracking and measurement to control and guide missiles to the target. Infrared guided technology is mostly served to the passive homing guidance. Infrared guided system consists of the infrared seeker, computer and actuator. As the tracking and measurement apparatus, infrared seeker makes up of the chopper wheel, infrared detector and optical system. Infrared seeker is mainly used to detect and collect heat radiation, then encoding the position of the target in space after modulation, thus output pulse sequence which includes target’s spatial direction information after photoelectric conversion. The pulse sequence will further output to the torquer of seeker and drive seeker’s optic axis to track the target. The performance of seeker is directly reflected in the capacity of missile’s traceability. In fact, infrared guided missile magnet has long been considered as the bright pearl of the crown in AlNiCo magnet area.

The seeker gyrorotor is the core component of the whole seeker. High accuracy guidance system requires its seeker gyrorotor has low power consumption, high accuracy and stability, therefore, magnetic support rotor gyro has been widely applied to the design of seeker gyrorotor. The essence of magnetic support is the weight of suspension and load it suffered can be balanced by ponderomotive force generated by adjustable magnetic field. As the provider of magnetic field, infrared guided missile magnet which also known as primary mirror magnet, its magnetic properties will directly impact the quality of the seeker. Primary mirror magnet integrates optical part, gyrorotor and magnet together, then magnets should have enough strength, dynamic unbalance, and optical mirror quality besides superior sine wave.