Share this article

How are neodymium magnets made?

ISO 9001:2015 Neodymium magnet outlines the standards for a quality management scheme, concerned with its delivery of the neodymium magnets that are satisfactory to both customers and the statutory authority. They also work to enhance consumer satisfaction by effectively implementing the ISO 9001 system, including mechanisms for system improvement and assurance of compliance with customer and applicable legislative and regulatory requirements.

Neodymium magnets have substantial remanence (Br), coercivity (bHc & iHc), and Maximum energy products (BHmax) than other types of permanent magnets but at a lower Curie temperature.

Here’s what the standards we have mentioned above mean for neodymium magnets:

  • Remanence (Br) is the magnetization left behind in a neodymium magnet after removing an external magnetic field. Sometimes the terminology retentivity for remanence is measured in units of magnetic flux density.
  • Coercivity (bHc) measures the ability of neodymium magnets to withstand an external magnetic field without becoming demagnetized. Coercivity(bHc) is usually measured in oersted or ampere/meter units and is denoted HC.
  • Maximum Energy Product (BHmax) is the maximal value of the product of the B and H curve. (actually, it is the maximum of the product’s negative, −BH, since they have opposing signs). By choosing a neodymium magnetic material with a high (BH)max and choosing the aspect ratio of the neodymium magnet so that its −BH is equal to (BH)max, the required volume of the neodymium magnet is minimized.
  • The Curie Temperature is the maximum temperature at which a piece of neodymium magnet can be heated before losing its magnetic force permanently. And the magnetic saturation can not reach its original state when re-magnetized. 

How are Custom Neodymium Magnets Manufactured?

Neodymium magnets are unique and technical rare earth magnets with a complex and sensitive manufacturing process. Though relatively new and small, neodymium is well-established now to the point it trumps other permanent magnets like ceramic ferrite formerly used to make magnetic products.
The essential components of a neodymium magnet are neodymium, iron, and boron, which make up the chemical combination NdFeB. The neodymium magnet’s grade or intensity determines the specific ingredients. In ROBO magnetic, there is a vast array of Grades (N35-N52, 35M-50M, 33H-48H, 33SH-45SH, 30UH-28UH, 28EH-35EH, etc.) and coatings (Nickel, Nickel Copper Nickel, Nickel Copper Semi-Bright Nickel, Nickel Copper Epoxy, Nickel Copper Nickel Golden, Nickel Copper Nickel Stannum, Nickel Copper Zinc, Nickel Stannum, Black Nickel, Bright Nickel, Epoxy, Zinc, Dark Zinc, Color Zinc, Trivalent Zinc, and Passivation) to choose.
Here are the few steps involved in the production of neodymium magnets:

Material & Recipe

The material and recipe composition within neodymium magnets determine the Grade of neodymium magnets.

Composition of Grade N35 NdFeB alloy

Elements within NdFeB Percentage by weight
Neodymium (Nd) 25.6%
Iron(Fe) 55.7%
Boron (B) 5.4%
Gadolinium Iron (Gd-Fe) 12.3%
Aluminum (Al) 0.7%
Zirconium(Zr) 0.2%
Copper(Cu) 0.1%

The feed preparation of neodymium magnets is as follows:

Step 1. The operator cuts the raw materials used in the formula into the size required by the recipe and performs degreasing, rust removal, and impurity removal according to the process requirements.

Step 2. The operator cuts the pure iron to a size of no more than 300 mm, and after confirming that the weight is no more than 80 kg, it is loaded into the iron washing machine for cleaning time for 15 minutes.

Step 3. The operator first performs the hot water degumming process on the corners, setting the water temperature to 80 degrees and the time for 20 minutes, then degreasing, and then drying them in an oven. The temperature of the range is controlled at 250 degrees. The time is 2 hours.

Step 4. The operator will use the hexagonal drum to remove the oil for the loading of less than 60 kg, tighten the cover plate after adding the cover, test run, check that there is no water leakage, and turn it.

Step 5. The operator puts the leftovers into the tray according to the process requirements. Each tray is less than 50 kg, put the tray into the oven after confirming that the stove is powered off, turn on the power, and set the time according to the process requirements and temperature. Take the material after turning off the power.

Melting and Milling

All the elements required to formulate the types of magnetic material picked by our client are put into a vacuum induction furnace; the elements are then heated and then melted to forge the alloy substance.

The new composition is then set to cool and form ingots. After the cooling process is complete, the ingots are ground into fine particles of at least three microns in a jet mill.

Pressing

In this manufacturing phase, the fine particles are subjected to magnetizing fields from a spiral wire that mimics a neodymium magnet once electricity passes through it; simultaneously, they are pressed into a mold. The direction of the particles in the mold and the direction of magnetic energy will determine if the magnetism of the final structure will be in the same direction or not.

Sintering

It is not the end of the process; the magnetized material is demagnetized at this point and re-magnetized later in the process. At this stage, the material is too soft and fragile and not helpful. The next step is to heat the material to its melting point in a sintering process. It fuses the powdered magnetic particles. This process takes place in an oxygen-free and inert environment.

Cooling

In most cases, the heated material is rapidly cooled using a technique known as quenching. This rapid cooling process minimizes areas of weak magnetism and maximizes performance. However, at this stage, the raw neodymium magnet is molded into the desired shape, but it is so hard that a diamond-coated cutting tool is required.

A Coating for all Applications

The last step before re-magnetizing the material is critical. Neodymium magnets are so hard that they can easily break or chip and must be coated, cleaned, dried, and plated. There are many different types of coatings used in neodymium magnets, the most common being nickel-copper-nickel mixtures. Still, they can also be coated with other metals, as well as rubber or polytetrafluoroethylene (PTFE).

The Neodymium Magnet

After coating, the finished material is placed in a coil and magnetized again. When an electric current passes through the coil, a magnetic field is generated three times the strength required by the neodymium magnet. It is a very effective process and can be ejected from the coil like a ball if the neodymium magnet is not held in place.

In the sintering phase, some neodymium magnets might be made using the bonding method, which is less effective and produces weaker neodymium magnets. Sintered neodymium is the best type of neodymium magnet with a high-performance application.

ROBO magnetic uses sintered neodymium magnets to form a wide variety of shapes and custom fabrications for use by their customers.

Neodymium Magnet Rating

Neodymium magnets are a type of rare-earth magnet and the most potent permanent magnets in the world. They are also known as NdFeB magnets or NIBs because they are composed primarily of neodymium (Nd), iron (Fe), and boron (B). They are relatively recent innovations in applications requiring permanent solid magnetic sources seen in magnetic separators, precision magnetic assemblies, and wind turbines. They have only recently become cheap for everyday use.

All neodymium magnets are categorized based on the neodymium magnet material from which they are made. Generally, the higher the grade (the number after the “N”), the stronger the magnet. The best class of neodymium magnets presently attainable is the N52. Each letter after the class indicates the temperature class of the neodymium magnet. If no letter follows the grade,  the neodymium magnet is neodymium at standard temperature.

Custom Neodymium Magnets Manufacturing

ROBO Magnetic has been a neodymium magnet manufacturer since 2006. Sixteen years of persistence in the industry goes without saying to establish we are one of the most experienced factories in China that manufacture and supply neodymium magnets.

We manufacture high-quality neodymium magnets for industrial, commercial, school, and personal needs and offer direct competitive factory prices. And export nearly eight hundred tons of neodymium magnets to overseas markets, such as Western Europe, Northern Europe, Southern Europe, Eastern Europe, South Asia, Southeast Asia, and North America.

The ROBO Magnet manufacturers retain many customized neodymium magnet sizes, grades, and coatings from other customers. We are very experienced in many complex neodymium magnet customizations. Moreover, the solid techniques, quality systems, and polished equipment make it more comprehensive and professional to offer custom neodymium magnets.

The market is filled with many manufacturers, and clients may be unable to pick what suits them. Yet, ROBO Magnetic delivers just a single kind of magnet – neodymium magnet by guaranteeing that the quality of products is unrivaled and proficient. We believe that by setting a standard that provides excellent quality neodymium magnets at competitive prices, we will be at the forefront of enhancing the lives of their clients and saving customers additional expenses.

Don’t be concerned about neodymium magnets’ shipping issues. ROBO Magnetic provides marine, air, express, and ground transportation.

You can acquire a free quote anytime by contacting them via online chat, online order form, email, or direct phone call.

Why ROBO Magnetic is the Best Manufacturer of Custom-made Neodymium magnets

Cutting-edge Technology

ROBO Magnetic uses Cutting-edge technology to provide the best service. We aim to make neodymium magnets stand out from other neodymium magnets.

Quality Control

The ROBO magnetic are proud owners of ISO 9001: 2015 certified products. ISO certification means that these products are marketable as they meet global standards. It means we manufacture high-quality neodymium magnets, but it also shows that we put customers’ needs first by ensuring every product’s safety.

Invincible Delivery Time

After ensuring quality, the following main concern is prompt delivery. ROBO magnetic aims to deliver the products to customers within one to two weeks after ordering. We value time as the most precious and take great care to utilize that of our clients.

Excellent Service

Service excellence has been tailored to assist customers in contacting this efficient company through their unique online service. ROBO magnetic believes we do more than sell by providing exemplary service to customers. ROBO magnetic excels in building customer relationships, and this is one of the many unique qualities that makes us as profitable as possible across generations.

ROBO magnetic services are always open to serve your rare earth custom order at any time and any day of the week. Contact them via online chats, emails, and direct phone calls. Your order is next up!

robo_magnetic

Article by

ROBO Magnetic Product Team

We are the manufacturer with 16 years of experience in custom neodymium magnets.

Need A Quote? Get in touch with us directly.

Share this article

0 0 votes
Article Scoring
Subscribe
Notify of
guest
0 Comment
Inline Feedbacks
View all comments