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Why Are Neodymium Magnets So Strong?

Hard disc drives, mobile phones, television video, and audio systems utilize neodymium magnets in information technology. Neodymium magnets are frequently employed in manufacturing on-off buttons, filters, ionizers, magnetic separators, and security and safety systems; in metal separators by grease filter manufacturers to more efficiently filter out iron powder from oil.

Neodymium magnets are in every household appliance. They are utilized in creating baby strollers that are magnetized to carriers, jewelry clips, badges, and identification tags.

How Are Neodymium Magnets Made?

The essential components of a neodymium magnet are the metal neodymium itself, iron, and boron, also known as NdFeB. What exactly goes into making a magnet depends on its grade or power.

Blend: A vacuum induction furnace is used to heat and melt every component needed to create the desired grade of the magnet for the alloy material. After cooling to form ingots, this combination is subsequently processed in a jet mill into tiny grains. Typically, grains are barely three microns in size.

Pressed: The ultra-fine powder is next compressed in a mold while magnetic energy is delivered to the mold. The source is a coil of wire that behaves like a magnet. The magnetism’s orientation is fixed while the mixture is squeezed! Anisotropic magnet is one in which the magnet’s particle structure matches the magnetization direction.

Sintered: The process is not finished at this point; instead, the magnetized material is demagnetized and will be re-magnetized later. The substance would be far too mushy and flaky to use.

Cooled: The material is nearly finished when quenching. Rapid cooling maximizes performance, minimizing weak magnetic zones. The raw magnets are now machined into the necessary shape. Diamond-plated cutting tools are required.

A COAT FOR ALL APPLICATIONS: Important work must be done before the material is re-magnetized. Neodymium magnets must be coated, cleaned, dried, and plated because of their extreme hardness, making them prone to breaking and chipping. Neodymium magnets can have a variety of coatings applied to them; the most popular is a nickel-copper-nickel alloy, but other metals, rubber, and PTFE can also be used.

NEW MAGNET FORMED: After plating, the material is re-magnetized by enclosing it in a coil that, when electrical current is sent through it, creates a magnetic field three times as strong as the magnet’s needed strength. If the neodymium magnet is not kept in place during this procedure, it could be launched off the coil like a bullet.

Why Are Neodymium Magnets So Strong?

Neodymium magnets are mighty due to their high levels of magnetic saturation, which enables them to produce substantial magnetic fields and their high resistance to demagnetization (coercivity). The highest energy product value (BHmax), expressed in MegaGauss Oersteds, is a magnet’s strength (MGOe).

Because of their power, neodymium magnets of any size can be useful. They are also incredibly versatile, so as we go about our daily lives in the modern world, neodymium magnets are always nearby.

However, the excellent grade must be selected for your application from the many possibilities available – neodymium magnets, samarium cobalt (SmCo) magnets, ceramic magnets, alnico magnets, bonded magnets, and injection molded magnets.

The BHmax will typically fall between 30 MGOe and 55 MGOe for Neodymium (NdFeB) magnets. The rule remains the same with neodymium magnets: higher numbers equate to stronger magnets. The MGOe of neodymium magnets is the highest of any permanent magnet material. N35, N38, N40, N42, N45, N48, N50, N52, and N55 are the most popular grades of neodymium magnets.

The lesson here, however, is not always purchasing the strongest of magnets. If your application system does not require the strength of a neodymium magnet, a samarium-cobalt or an alnico magnet will be more suited for the model; save yourself the stress and stick with that choice.

Neodymium Magnets Vs. Other Magnets

Neodymium, iron, and boron are the three main chemical components, whereas iron is the primary component of a regular magnet. It is the primary distinction between neodymium magnets and regular magnets.

Neodymium magnets are highly affected by temperature. No letter denotes a maximum operating temperature of 80° C for ordinary neodymium. A typical rating for neodymium 35 at increasingly higher temperatures goes – M, H, SH, UH, EH, or AH.

Strong magnets of rare earth elements like neodymium are known as neodymium magnets. It is a mixture of many metals, including iron, boron, and others. On the other hand, ordinary magnets are ceramic devices with ferrite as their primary component. Along with other metals like barium, iron(III) oxide makes up a significant portion of its composition. Due to their low price and tremendous power, these magnets are viral.

How To Make A Neodymium Magnet Stronger?

You must first determine whether the magnet in your product has been weaker over time or if it has always been weak. As we all know, a neodymium magnet has electrons inside of it that are initially oriented such that they point either north or south, depending on the polarity of the neodymium magnet. They can do this by speeding up electron mobility, which leads them to move from their initial positions. And the strength of a neodymium magnet is determined by how many electrons align in this configuration. In other words, the attraction is stronger when the electrons are more.

A given consumer product’s magnet has the greatest concentration of electrons pointing in the same direction when you first use it. Its magnet is, therefore, as powerful as it can be to ensure that it can function effectively. However, if the product’s magnet has been deteriorating since you bought it, the neodymium magnet has probably been weak since it was made; in most cases, the only option is to discard it.

The weak magnet must be placed inside the magnetic field of a much giant, stronger neodymium magnet. The larger, stronger neodymium magnet should be placed precisely next to the smaller, weaker neodymium magnet to get the best results since it will help realign the weaker magnet’s out-of-axis electrons.

The giant, a stronger magnet, can then be used to stroke your weaker neodymium magnet. Please be aware that to align the flowing electrons further, you must stroke them from one polarity to the other. Various factors, including heat, radiation, and electricity, significantly reduce a magnet’s magnetic field.

How To Find The Grade Of A Neodymium Magnet

A magnet’s grade is a reliable indicator of power. Higher numbers denote a stronger neodymium magnet. Neodymium magnets come in grades ranging from N35 to N52. Application, cost, size, operating temperature, and many other aspects are influenced by magnetic grade.

The Maximum Energy Product of the Magnet Material, stated in MGOe, is an actual material attribute that gave rise to the number (MegaGauss Oersteds). The BH Curve’s most vital point on the magnet’s demagnetization curve.

The grade or N number of a magnet affects the pull force it produces. You can roughly double the draw force by doubling the N number.

The stronger the magnet, the higher the material grade number. One significant exception to this rule is Alnico. Grade and strength do not typically correlate as Alnico is size-dependent.

When choosing the material grade for your application, take into account the following factors:

  • Initial Maximum Operating Temperature 

A key consideration for selecting a magnet material is its maximum operating temperature. Therefore, it is essential to determine your operating temperature range before choosing your grade.

  • Required Holding Force or Magnetic Field Density

We issue a warning when evaluating the necessary magnetic field density or holding force – don’t choose a higher grade than you may need. Although it may be tempting to select the material grade with the maximum strength, it might not be suitable for the use you have in mind. It may also be unnecessarily expensive to select a grade higher than you want, especially if creating a high-volume consumer application.

  • Resistance to Demagnetization 

The demagnetizing resistance is the final factor when selecting a magnet grade. This aspect probably has a significant impact on your final design. The intrinsic coercive force (HCI) is closely associated with your maximum operating temperature. HCI is the demagnetization resistance. The higher your working temperature, the higher the HCI. Heat is the leading cause of demagnetizing. However, it is not the only one. Other essential elements for demagnetizing resistance are the geometry of your part and the magnetic fields generated in your system.

The damage is frequently irreparable after demagnetization takes place. Starting your project with the proper material grade will significantly impact cost and potential redesign time.

Neodymium magnets are the new age technological panacea. With the information provided above, we hope it will help you make more informed choices for your projects, and when in doubt, you have the ROBO magnetic company to see you through.

The ROBO magnetic team is an experienced neodymium manufacturing company that will help you discover the custom magnet required for your project. We have over sixteen years of experience working with customers and helping them choose the best neodymium magnet for their projects. We keep the prototype of customers’ custom orders to help guide your choices.

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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.

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