Neodymium iron boron process flow

1. Raw material preparation and pretreatment

Process description: Weighing, crushing, cutting, and rust removal pre-treatment of raw materials.

Process equipment: steel bar cutting machine, drum polishing machine, etc

2. Melting

Process description: The pre treated raw materials such as praseodymium neodymium, pure iron, and boron iron are proportioned and added to a vacuum melting furnace. They are then melted at high temperature under argon gas protection and subjected to strip throwing. Make the product composition uniform, with high crystal orientation, good organizational consistency, and avoid ɑ- The generation of Fe.

Process equipment: Vacuum melting furnace

3. Hydrogen explosion

Process introduction: Hydrogen explosion (HD) process utilizes the hydrogen absorption properties of rare earth intermetallic compounds to place neodymium iron boron alloy in a hydrogen environment. Hydrogen enters the alloy along the thin layer of neodymium rich phase, causing it to expand, explode, and break. It cracks along the neodymium rich phase layer, ensuring the integrity of the main phase grains and the interface phases between the neodymium rich grains. The HD process makes the casting of neodymium iron boron very loose, greatly improving the powder production efficiency of the airflow mill and reducing production costs.

Process equipment: Vacuum hydrogen treatment furnace

4. Powder making

Process introduction: Airflow milling powder is produced by high-speed collision of materials themselves, which has no wear or pollution on the inner wall of the grinding chamber and can efficiently prepare powder.

Process equipment: Airflow mill

5. Forming orientation

Process introduction: The function of orientation is to rotate the c-axis of the easily magnetized direction of the disorderly oriented powder particles in the same direction. The main purpose of pressing is to crush the powder into a certain shape and size, while maintaining the grain orientation obtained in the magnetic field as much as possible. We design to use a forming magnetic field press and an isostatic press for secondary molding. For special-shaped magnets, special mold fixtures are used for direct molding. After sintering, the magnets only need to undergo slight surface treatment to be put into use, greatly saving materials and subsequent processing costs.

Process equipment: magnetic field press, isostatic press

6. Sintering

Process Introduction: Sintering is a simple and inexpensive method that can change the microstructure of materials to improve their magnetic properties by causing a series of physical and chemical changes to occur under high temperature during crushing. Sintering is the post forming process of materials, which has a crucial impact on the density and microstructure of magnets.

Process equipment: Vacuum sintering furnace

7. Mechanical processing

Process description: The neodymium iron boron magnets obtained after sintering are all blanks and require further mechanical processing to obtain products of various sizes, sizes, and shapes. Due to its brittleness and poor mechanical properties, neodymium iron boron magnets can generally only be processed by grinding and cutting.

Process equipment: surface grinder, double end face grinder, chamfering machine

8. Surface treatment

Process description: Surface treatment of various shapes of rare earth permanent magnets, such as electrophoresis, galvanizing, nickel, nickel copper nickel, and phosphating, to ensure the appearance and corrosion resistance of the product.

9. Finished product inspection and packaging

Process description: Various magnetic properties, corrosion resistance, high temperature performance, etc. of the product are tested, and after meeting the standards, packaging is carried out to meet the various needs of customers.