Sintered NdFeB manufacturing process-jet mill

Jet mill (JM) powder making is a new type of powder making method that uses high-pressure airflow (usually high-purity nitrogen) to accelerate powder particles to supersonic speed in the airflow grinding chamber, causing the powder particles to collide with each other and break.

The specific process is: mix the crushed hydrogen flakes (SC) with a certain proportion of antioxidant, then add it to the airflow mill feeding bin, add it to the airflow grinding chamber according to the quantitative amount, and high-pressure nitrogen (7kg) is sprayed from the four nozzles of the grinding chamber. , accelerate the material to supersonic speed to form a fluidized bed, and the particles collide with each other and break. The diameter of the broken particles is distributed between 1-8 μm.

Depending on the performance and distribution of the materials, the average airflow milling powder size SMD is between 2.5-4μm. The powder produced by airflow milling is uneven and requires three-dimensional mixing. Before mixing, a certain proportion of lubricant and antioxidants are added to the material tank according to the process to control the oxygen content and improve the molding orientation performance.