Five Major Production Processes of Sintered NdFeB Permanent Magnets.

Sintered NdFeB permanent magnets are an important type of permanent magnet material, characterized by high magnetic energy product, high magnetic saturation field strength, and high magnetization field strength. They are widely used in electric vehicles, motors, induction cookers, power tools, and other fields.

Five major production process steps for sintering neodymium iron boron permanent magnets
The production process of sintered neodymium iron boron permanent magnet materials generally includes five steps: raw material processing, preparation of magnetic powder, magnet forming, pre sintering, and sintering. This process requires strict process control and operation under high temperature and high pressure conditions to ensure the performance and quality of the magnet.

Raw material processing. The raw materials for neodymium iron boron magnets mainly include neodymium iron boron powder, additives, and binders. Neodymium iron boron powder is the main raw material for preparing magnets, which is generally synthesized from rare earth metals and elements such as iron and boron through hydrogenation reduction method. Additives are used to improve the performance and processability of magnets, and commonly used additives include boron, titanium, etc.
Preparation of magnetic powder. The neodymium iron boron powder after raw material processing needs to undergo a series of processes to improve its magnetic properties. The grinding process is to grind rough powder to make its particle size uniform. Next is magnetization treatment, which applies an external magnetic field to magnetize the powder and increase its magnetization strength. Then there is washing and drying to remove impurities from the powder and improve its purity.
Magnet forming. Magnet forming is the process of mixing processed magnetic powder and a matching binder in a predetermined ratio, and then shaping the mixture into the desired shape of the magnet through a pressing process. Common shapes include disc, column, and ring. There are two main molding methods: dry pressing molding and injection molding.
Pre burned. The formed magnet needs to undergo a pre firing process, with the main purpose of removing volatile substances and residual moisture from the binder, and avoiding the formation of pores and cracks during the sintering process. The pre firing conditions are generally between 200-600 degrees Celsius, and the time depends on the size of the magnet and the required performance,
sinter. Sintering is a key step in the preparation of sintered neodymium iron boron permanent magnet materials. The formed magnet needs to be sintered under high temperature and high pressure conditions to form a dense crystal structure and improve its magnetic properties. The sintering temperature is generally 1100-1200 degrees Celsius, and the sintering time depends on the size of the magnet and the required performance. The sintered body needs to undergo processes such as grinding and cleaning to obtain the finished sintered neodymium iron boron permanent magnet material.
Conclusion
The production process of sintered neodymium iron boron permanent magnet materials is a complex and critical process, which imposes strict requirements on material preparation and processing techniques. Sintered neodymium iron boron magnets, as a type of permanent magnet material, have the characteristics of high magnetic energy product, high coercivity, and high magnetic energy density, and are widely used in daily life.