Alloying and Melting: It is the beginning process for sintered NdFEB magnet to undertake the manufacturing processes. We start by melting neodymium, iron, boron, and any extra elements together. This process goes on for hours to be accomplished and needs furnace temperature to reach about 1300°.
Hydrogen Decrepitation: After the alloy cools, it’s broken down using hydrogen gas. The hydrogen causes the alloy to crack into chunks, which makes the next grinding step easier.
Jet Milling: These chunks are ground into a fine powder using high-speed jets. You want really tiny particles here—think of it like turning rock salt into flour.
Pressing: The powder is then pressed into shape while under a magnetic field. That magnetic field is important—it lines up the magnetic domains to give you a stronger final magnet.
Sintering and Annealing: Now comes the heat. The pressed magnets are baked at high temperatures to solidify them. After that, they’re annealed—basically given a heat soak—to relieve stress in the material and enhance magnetic properties.
Machining: Once cooled, the magnets are cut or ground down to the exact sizes needed. Moreover, the machining process comes in three different types, including:
Cutting Processing: A machining process that cuts square columns and cylindrical magnets into disc-shaped and square-shaped elements.
Shape Processing: It processed square and round magnets into tile-shaped, fan-shaped or other complex-shaped magnets.
Punching Processing: That makes the square and round bar magnets turn into cylindrical or square cylindrical magnets.
Surface Treatment: Neodymium magnets don’t like moisture—without protection, they’ll rust. So we coat them, usually with nickel, zinc, or epoxy, to keep corrosion at bay.
Magnetization: Last but not least, the magnets are hit with a powerful magnetic field to lock in their magnetic orientation. After this step, they’re ready to go.
