How Are Neodymium Magnets Made? The Complete Guide to Manufacturing NdFeB Magnets

What are Neodymium Magnets?

Neodymium magnets are very, very strong. They are the strongest permanent magnets you can find!

• They are made of Neodymium (that’s a metal!), Iron, and Boron.
• We call them NdFeB magnets for short. (Nd = Neodymium, Fe = Iron, B = Boron).
• Sometimes, we add a tiny bit Dysprosium (Dy) or Praseodymium (Pr).

These magnets are used in lots of things:

• Toys
• Computers
• Cars
• Phones
• Wind Turbines that make power.

Want to see different types of neodymium magnets! Checkout our Custom Neodymium Magnets page!

How We Make the Magnets: Step-by-Step

It’s like baking a cake, but with metal, not flour and sugar!

Step 1: Get the Raw Stuff

First, we need to get all the rare-earth elements. These are like the ingredients.

• Neodymium (Nd): This is the main rare-earth element.
• Iron (Fe): Lots of iron!
• Boron (B): Just a little bit of boron.
• Dysprosium (Dy) or Praseodymium (Pr): These are additives, they improve stability.
• China has the most rare-earth elements.

We are very good at getting the best stuff. We check it to make sure it’s very, very pure. Like, 99.9% pure! This improve the magnetic susceptibility.

Step 2: Mix and Melt!

We use a special oven. It’s called a Vacuum Induction Furnace.

• It’s vacuum inside. That means no air!
• We melt all the metals together. It gets VERY hot!
• This makes a special mix called an alloy. The NdFeB alloy composition is very important.
• We control the oxygen content. Too much oxygen is bad! This process reduces the Eddy current losses.

We have big ovens. We can make lots of magnets!

Step 3: Make Powder

Now we have a big block of alloy. We need to make it into a very fine powder.

1. Hydrogen Decrepitation: First, we use hydrogen gas. It makes the alloy break into small pieces.
2. Jet Milling: Then, we blow the pieces around very fast! They bump into each other and become even smaller. Like sand! This is powder metallurgy.
3. Magnetic alignment: Create magnetic field orientation that impacts the later magnetic anisotropy.

We use a special press. It’s called an Isostatic Press. It pushes the powder very hard from all sides. This makes the magnet strong. This step also contributes to the magnet’s electrical conductivity and magnet’s tensile strength.

Step 4: Sintering (Baking!)

Now we have a block of pressed powder. It’s not strong yet, and is very brittle.

• We put it in another special oven. It heats up to 1080-1150 degrees Celsius! Very, Very hot!
• This is called sintering. The tiny pieces of powder join together.
• Then we cool it down slowly. This is batch annealing.
• In this stage, we complete the alloy homogenization in specific heat treatment cycles.

We are very careful with the heat. It makes sure the magnets are just right. We check the grain size and control the cooling and quenching. This stage impacts the magnet’s brittleness.

Step 5: Make it the Right Shape + Protect It

The magnet is now strong, but it’s not the right shape. And it will rust!

1. Cutting and Grinding: We use special tools to cut and grind the magnet. We make blocks, discs, rings, and other shapes. We make sure the magnet’s shape is perfect.
2. Coating: We put a special coating on the magnet. This protects it. It’s important to choose the right type of Magnet Coating .
   • Nickel plating is common. It’s shiny!
   • Epoxy coating is good too.
   • Zinc.
   • Or even gold!

We test the coating. It needs to be strong so the magnet will not rust. Corrosion-resistant coatings are a must!

Step 6: Make it a Magnet!

The magnet is almost ready. But it’s not magnetic yet!

• We use a very strong electric pulse. This is a magnetizing fixture.
• It makes all the tiny parts inside the magnet line up.
• Now it’s a super strong magnet!
• We also use Electromagnetic forming to guarantee all the magnetic domains are aligned.
• We always use magnet safety protocols.

We test every magnet. We check how strong it is using special tools. We make sure it has the right magnetic flux density.

Step 7: Additive Manufacturing

We use magnet printing (additive manufacturing) on some of our magnets, using Chemical vapor deposition.

Sintered vs. Bonded Magnets

There are two main types:

• Sintered NdFeB Magnets: These are the ones we mostly make.
  • They are very, very strong.
  • We make them in different shapes.
  • See our Customized NdFeB Magnets page.
• Bonded NdFeB Magnets:
  • We mix the powder with plastic.
  • We can make very complicated shapes.
  • We have to use special Dust Control.

What Makes a Good Magnet?

There are good magnets and bad magnets. Here’s what to look for.

1. Grade: This tells you how strong the magnet is.

   • N35 is good.
   • N52 is the strongest! We make all the grades, from N35 to N52.
   • The higher the Magnet Grade, the greater the Energy Product (BH max).

2. Temperature Rating: Magnets can get weak if they get too hot.

   • N is for normal temperatures.
   • M, H, SH, UH, EH, AH can handle more heat. N42SH is a good one for hot places. If you don’t take this into consideration, you might see thermal aging effects!
   • We make special magnets like N33M, or a N48H that can handle high temperatures. Find out more about the different Magnet Grades available.

3. Coating:

   • Nickel is good for most things.
   • Epoxy is good if the magnet might get wet, and is cheaper.
   • If the magnet will resist moisture, we use PTFE Coating, or Teflon Coating.

4. Size and Shape:

   • Make sure it fits! We do magnet cutting/shaping. This contributes to the magnet’s general durability.

We can help you pick the right magnet!

Where are NdFeB Magnets Used?

They are everywhere!

• Electronics:
  • Mobile Devices: Like your phone!
  • Audio Equipment and Speakers: For music! See the speaker magnets we offer.
  • Data Storage.
  • We offer completely custom ndfeb for this application.
• Cars: Especially electric cars! They use lots of magnets. We specialized in manufacturing NdFeB for the automotive industry .
  • We make magnets for Electric Vehicles motors.
  • We also make specialty ring magnets.
  • New cars with Autonomous Driving and ADAS need magnets!
• Wind Turbines:
  • Wind power generation needs big, strong magnets.
  • These applications use neodymium permanent magnet generators. We make magnets for wind turbines .
• Household Appliances:
  • Even your washing machine has magnets!
  • We make Energy-Saving Motors for fridges!
• Industrial Equipment:
  • Industrial Motors use strong magnets.
  • Servo motors use our magnets.
• Aerospace
  • Used in Aerospace Engines and Electric Propulsion Systems
• Medical Devices:
  • MRI machines use very big magnets!
• Power Tools:
  • Handheld Tools and Gardening Tools use magnets.
• Toys
• Tidal and Wave Energy Generators
• Photovoltaic Tracking Systems
• Education and Research
• Magnetic Modules, magnetic Jewelry, magnetic Sheets, magnetic systems

You see, NdFeB, permanent magnets are everywhere!

Why Pick Us?

• We make the best magnets. We are expert.
• We do everything, from getting the raw material to shipping the finished magnet. In protective packaging.
• We are fast! Usually 2-4 weeks.
• We care about the Earth. We recycle old magnets. We follow all the relevant environmental regulations.
• We have ISO 9001 Certification. That means we are very, very good! We offer quality control standards that include magnet performance testing, magnet durability testing, coating adhesion testing and leakage flux analysis.

How to Get Your Magnets

1. Tell us what you need. We have a special tool to help.
2. We’ll tell you how much it will cost.
3. We can send you a sample if you are buying lots of magnets.
4. We ship all over the world! With specific magnet shipping regulations.

Questions You Might Have (FAQ)