Bonded magnets appeared in the 1970s. At that time, SmCo was commercialized. The market for sintered NdFeB permanent magnets was very good, but it was difficult to precisely process into special shapes, and it was prone to cracking and breakage during processing. Problems such as falling edges and corners are also difficult to assemble, which limits their application. In order to solve this problem, the permanent magnet is pulverized and mixed with plastic, and pressed in a magnetic field, which is probably the most original manufacturing method of the bonded magnet. Bonded Nd-Fe-B magnets are widely used due to their low cost, high dimensional accuracy, large shape freedom, good mechanical strength and light weight.
Bonded NdFeB magnets have lower magnetic properties than sintered NdFeB, but because of their convenience in manufacturing multi-stage magnetized ring magnets, they have excellent performance uniformity and uniformity, and are easy to be integrated with other metal or plastic parts. , far higher than the magnetic properties of bonded ferrite, is widely used in various types of micro-motors and sensor systems. The specific use of bonded NdFeB can be divided into:
Digital products: hard disk drive magnets (HDD) - this is currently the largest application area for bonding NdFeB
Office OA products: transmission motor for printer, motor for scanner, synchronous machine for copying machine (STP), magnetic roller for laser printer, etc.
Automotive motor and magnetic sensor products: including EPS power steering sensor magnet, wiper motor, window motor, seat adjuster motor, etc.
Other types of industrial and household motors: mainly include various types of servo motors, motors for electric tools, air conditioning refrigeration motors, etc.
Due to the large difference in magnetic properties and molding, the intersection of bonded NdFeB and sintered NdFeB is not large. Bonded NdFeB is mainly used in the field of hard disk drive spindle motors and micro-motors with low power, and sintered NdFeB is more used in the field of high-power drive motors.