The Manufacturing Process of Sintered Neodymium Magnet – How Neodym Magnets are made?
Sintered neodymium magnet is manufactured by vacuum powder metallurgy process. The manufacturing process is as follows:
1. Raw Material
Neodymium (Nd), Iron (Fe), Boron (B) and other addictives are measured according to the preferred element composition.
Raw NdFeB material Raw Material of Nd, Pr and Fe NdFeB Material Component Neodym Magnet Component Analysis
There are two ways to melt the raw material and make into roughcast neodym material. One is Melting-Crushing. This process is simple, but the particle size of the magnetic powder is quite big. The other is Hydrogen Decrepitation, which can obtain the magnetic powder with smaller particle size.
2.1 Melting – Crushing
The measured elements are mixed and fed into the vacuum induction furnace and melted into alloy. The alloy will be crushed into particle by the Crusher.
NdFeB Melting Machine High Vacuum Melting Furnace Raw material are melted into alloy NdFeB Semi-finish material after Melting Magnetic alloy initial form
NdFeB Crushing Machine Jaw Crusher Alloy are crushed into particle NdFeB Semi-finish Material after Crushing Magnetic particle form after crushed
2.2 Strip Casting – HD
The flakes of neodym cast alloys are prepared by using the strip casting technique. Then they are put into the HD machine, with vacuum and heat up to 700~800°C. The hydrogen enters the material in the spaces between the atoms and causes the material to expand. The differential expansion generates stress in the ingot and the alloy flakes break down into fine particle.
Rapid Solidification Strip Casting
NdFeB Cast Strip Machine Vacuum Strip Casting Furnace NdFeB Strip Neodym alloy flakes are made by strip casting Strip Casting Melt Magnetic alloy initial form
NdFeB HD Machine Hydrogen Decrepitation Furnace Alloy flakes break down into fine powders by HD Magnetic particle form change during HD
The high-pressure nitrogen flow in the jet mill blow the neodym particles with very high speed and make them collide with each other to be shattered. In order to guarantee the purity of the powder particles, and to prevent the detonation caused by the exposure to air, the entire milling process is under the high-purity inert gas protection.
NdFeB Milling Machine Jet Milling Furnace NdFeB Milling Process Particle become fine powder during jet milling flow Magnetic powder form after jet milling
The powders are pressed into shape in a magnetic field to obtain a preferred magnetization direction.
NdFeB Pressing MachineIsostatic Press Machine NdFeB Pressing ProcessPowders are pressed into shapes NdFeB Pressing ProcessIsostatic press situation
The material is sintered in the vacuum into roughcast under 1080 degree.
NdFeB Sintering Machine Vacuum Sintering Furnace Raw magnets are sintered in vacuum furnace The initial magnet cell form after sintered
The sintered neodym semi-finished products are made into proper shapes after mechanism process.
Wire Cutting Machine NdFeB Grinding Process Raw magnets are cut into proper shapes NdFeB Semi-finish Material after Grinding The magnet form after machanism process
The Fe and Nd element in the neodym magnets are very easy to oxidative corrosion. So the coating is needed for protection. The common coating is Ni, Zn and Epoxy. You can find all information of our available surface treatments of sintered neodym magnets here.
Electroplating Production Line Magnets are electroplated with special coatings
Key measurements include remnant flux density, coercivity, and maximum energy product. Only those magnets that pass the inspection are sent to subsequent processes including machining and assembly.
NdFeB Inspcetion Workshop
Worker use callipers or other measure tools to inspect quality
The neodymium magnet will be placed in the magnetizing coils with a high voltage pulse magnetic field until it is completely magnetized. You can find all information of our Methods of Magnetization in our resource center.
NdFeB Magnetizing Machinem Impulse Type Magnetizer Magnets are magnetized in high magnetic field NdFeB Magnetization Magnetic cell form after magnetization
Packing Machine NdFeB Packing Process Magnets will be packed well with thick plastic foam and carton box
N40H Neodymium Iron Boron Motor Arc Magnets, Powerful Rare Earth Neodymium Segment Curved Magnet, permanent horseshoe sintered magnet, Stator and Rotor Magnet, dc permanent magnet motor generator, Permanent Magnet DC (PMDC) Motor Arc-shaped Magnets N40H Neodymium Iron Boron Motor Arc Magnets Parameter Part No. NSGN40H-78 Dimensions Customized sizes Material Sintered Neodymium-Iron-Boron (NdFeB) Shape Arc / […]
N38H Arc Magnets for Motorcycle Stator, Powerful Neodymium Motor Rare Earth Segment Curved Magnet, high coercivity Motorcycle Stator and Rotor Magnet, NIB REE Permanent Magnets, magneti permanenti per industria N38H Arc Magnets for Motorcycle Stator Parameter Part No. NSGN38H -77 Dimensions Customized sizes Material Sintered Neodymium-Iron-Boron (NdFeB) Shape Arc / Segment Plating Blue Zinc (zn) […]Magnet Manufacturing Process
Axial Flux Motor Magnet Segment Arc NIB N50, Neodymium Motor Rare Earth Segment Curved Magnet, PM Axial Flux Motors Magnet, AXIAL FLUX ELECTRIC MOTOR MAGNETS, REE Permanent Magnets N50, Super Strong Nd Magnets Axial Flux Motor Magnet Segment Arc NIB N50 Parameter Part No. NSGN50 -76 Dimensions Customized sizes Material Sintered Neodymium-Iron-Boron (NdFeB) Shape Arc […]Magnet Manufacturing Process
Neodymium Motor Rare Earth Segment Curved Magnet, N52 Curved NdFeB Magnet for High Efficiency Rotors Motors, REE Permanent Neo Magnets N52, Super Strong Nd Arc Magnets for electric motors, generators, couplings Neodymium Motor Rare Earth Segment Curved Magnet for High Efficiency Rotors Motors Parameter Part No. NSGN52 -75 Dimensions Customized sizes Material Sintered Neodymium-Iron-Boron (NdFeB) […]Magnet Manufacturing Process