At present, magnetic materials are mainly divided into permanent magnetic materials and soft magnets, permanent magnetic materials can be permanently preserved, mainly including ndfeb as the representative of the alloy permanent magnetic materials and ferrite permanent magnetic materials. The magnetism of a soft magnet can be magnetized by external action, but the magnetism is also easy to disappear.
NdFeB is the third generation of rare earth permanent magnetic material, composed of a large number of neodymium, iron, boron three rare earth elements, of which neodymium element accounted for 25%~35%, iron accounted for 65%~75%, boron accounted for about 1%. Ndfeb has the advantages of high remanence density, high coercivity and high magnetic energy product, which is the most magnetic permanent magnet material so far.
NdFeB has higher BH than ferrite, magnetic force is 3-5 times higher than ferrite, and its stability is strong, magnetic force is also relatively controllable. With the continuous development of the new energy automobile and robot industry,NdFeB is expected to become the main direction of future magnetic material development.
According to the production process classification, NdFeB can be divided into sintered NdFeB and bonded NdFeB, sintered NdFeB is the use of powder metallurgy process, smelted alloy made of powder and pressed in the magnetic field; Bonded NdFeB is made of NdFeB powder and resin or rubber extrusion molding. Compared to sintered NdFeB, bonded NdFeB is not easy to corrosion, production difficulty is low, but the magnetic properties is lower than sintered NdFeB.
In recent years, the production and sales of NdFeB in China have been greatly improved. By 2014, the production and sales of NdFeB in China has reached about 320 million kg, which is close to the production and sales of ferrite magnets, making it the fastest growing type of all magnetic materials.
NdFeB as the current performance of the most excellent permanent magnet, its performance effect is also different, the most sophisticated is high performance NdFeB. High-performance NdFeB permanent magnetic materials are sintered NdFeB permanent magnetic materials with the sum of Hc(j KOe) and (BH) Max (MGOe) greater than 60, whose magnetic properties, coerceability, magnetic remanence, temperature characteristics and other properties are much better than ordinary NdFeB permanent magnetic materials.
High performance NdFeB because of its excellent performance is widely used in new energy vehicles, frequency conversion air conditioning, energy-saving elevator, magnetic levitation train, intelligent robot, wind power generation and other fields, can greatly reduce the application of the product volume, reduce the quality of the product and can provide higher efficiency, so the attention.
Current global high performance NdFeB accounted for 30% of the total output of NdFeB ~ 30%, and the yield increased year by year, the world in 2012, there are about 38000 tons of high-performance NdFeB production, 2015 annual output reached 46000 tons, annual average growth rate of over 6.5%, as the global new energy cars and the continuous development of the industrial robot, is expected to remain high performance NdFeB industry rapid development trend.
The world NdFeB production enterprises are gradually starting to spread to China. At present, there is no large-scale ndfeb production enterprise in the United States, and all its production capacity has been transferred to China. Two major European sintered NdFeB manufacturers, Finland's Neorem and Germany's VAC, merged in 2007 and began to set up production facilities in China. Meanwhile, Japan, once the world's largest NdFeB producer, is shifting capacity to China.
At present, the production of NdFeB in China has accounted for more than 90% of the world's NdFeB permanent magnetic material production, among which the proportion of high-performance NdFeB permanent magnetic material in the world has been rising, now nearly 60%. With the increased regulation and cost of NdFeB production in Europe, the us and Japan, the proportion of NdFeB production in China is expected to further increase in the future. It can be said that China's NdFeB production determines the global supply trend.
In recent years, China's NdFeB capacity has expanded rapidly. The raw material capacity has expanded from 8,000 tons in 2000 to over 400,000 tons in 2014. Meanwhile, the capacity utilization rate is very low. At present, China's NdFeB excess capacity is concentrated on low-end products, low-end NdFeB production accounted for nearly 80% of the total production.
At the same time, due to the low entry threshold of low-end NdFeB production, the industry capacity is relatively scattered, and the small and medium-sized NdFeB production enterprises with less than 3000 tons of capacity have become the main supply force. Due to the low end NdFeB price in recent years, many small businesses have shut down. Capacity concentration has increased.