NdFeB permanent magnet materials are based on the intermetallic compound Nd2Fe1₄B. Compared to cast Al-Ni-Co series permanent magnet materials and ferrites, NdFeB possesses extremely high magnetic energy product and coercivity, capable of attracting objects weighing 640 times their own weight. The advantage of its high energy density has enabled NdFeB permanent magnet materials to be widely used in modern industry and electronic technology, making it possible to miniaturize, lightweight, and thinen devices such as instruments, electromechanical motors, and magnetic separation and magnetization systems. A key advantage of NdFeB is its high performance-to-cost ratio and excellent mechanical properties, which make it easy to machine; however, its disadvantage lies in a low Curie temperature point, poor thermal characteristics, and susceptibility to powdering and corrosion. These issues must be addressed by adjusting its chemical composition and applying surface treatment methods to meet practical application requirements.
The neodymium-iron-boron manufacturing process uses powder metallurgy technology. Raw materials such as neodymium, dysprosium, iron, cobalt, niobium, praseodymium, aluminum, copper, and boron-iron are smelted into alloy steel ingots using an intermediate-frequency induction melting furnace. These ingots are then crushed into powder with a particle size of 3–5 μm, pressed into shape under a magnetic field. The formed green mass is sintered densely and aged in a vacuum sintering furnace to produce a permanent magnet blank with desired magnetic properties. After processing steps including grinding, drilling, and slicing, and surface treatment, the final neodymium-iron-boron product required by the customer is obtained.
