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Will neodymium magnets rust?

Yes, neodymium magnets will rust.

A neodymium magnet is one of the rare earth magnets which is the strongest permanent magnet. Neodymium, boron, and iron are the main constituent.

The neodymium magnets we sell today are rated to have their magnetic strength for years if kept in dry conditions and not subjected to excessive heat, radiation, or external magnetic fields.

However, they can corrode when they’re not correctly sealed and come in contact with oxygen and moisture.

You might also wonder how to avoid corrosion and how neodymium magnets can be protected from the environment and appropriately sealed?

There are a few different ways to go about this, some of which are much easier than others.

Let’s find out!

How to Avoid Neodymium Magnet Corrosion?

There are different techniques for preventing corrosion in Neodymium magnets. Some of the noteworthy ones are mentioned under:

  • Phosphorization

Phosphorization is a process in which a thin layer of coating is applied to the surface of a neodymium magnet. This coating protects the neodymium magnet against corrosion to last longer.

Phosphorization has numerous purposes, including protecting base metal from corrosion to a certain extent and acting as a primer before painting. Besides, it also improves the film layer’s adhesion and corrosion resistance.

There are two methods of phosphorization. The first is electrochemical phosphorizing, which applies a thin layer of coating to the surface of the neodymium magnet using an electrical current.

The second is called chemical phosphorizing, and it involves dipping the neodymium magnet into an acidic solution containing phosphorus.

The phosphorized coating on neodymium magnets prevents corrosion by forming a barrier between oxygen and the metal.

That allows neodymium magnets to have long lifespans.

  • Electroplating

Electroplating is a process that involves immersing a material in a solution of an electrolyte, which is usually an acid or base, and an electric current.

This process can prevent neodymium magnets’ corrosion by coating them with a thin metal layer such as copper or nickel.

This metal coating will make the neodymium magnet more resistant to corrosion because it forms a barrier between it and any other substances that may cause it to corrode.

Besides, it enhances the aesthetic effects and improves electrical conductivity, wear resistance, and reflection.

  • Electrophoresis

Neodymium magnets are coated with a thin metal layer to improve corrosion resistance, durability, and strength. Besides, it also enhances the resistance to acid, alkali corrosion, and salt spray.

Applying this coating is known as electrophoresis, a form of an electrochemical layer.

Electrophoresis uses a DC to move charged particles (ions) through a solution.

In the case of neodymium magnets, the ions are positively charged metal atoms that will adhere to the surface of the neodymium magnet.

Neodymium Coatings

Many different coatings prevent corrosion on Neodymium magnets, but the prevalent ones are nickel, nickel-copper, and zinc.

However, the following are some of the most effective coatings along with their characteristics:

  • Nickel Copper Nicker (Ni-Cu-Ni)

The most common coating is nickel copper nickel, a silvery-white metal made from iron and carbon.

It’s a relatively soft metal but strong and resistant to oxidation. Besides, it’s electric, and heat conductivity is also good.

Nickel copper nickel coating has a shiny metallic color and thickness of 12 micrometers, and its widely used for coating neodymium magnets and electroplating applications due to its reasonable price-to-performance ratio.

  • Epoxy resin (Ni-Cu-Ni-Epoxy)

Epoxy coating is also very durable and can be applied in multiple layers for extra protection from the elements.

This coating is excellent for outdoor applications with lots of moisture around!

The coating is thick—about 10 micrometers—and black.

However, it’s not shock-resistant and will crumble quickly.

So, moisture can cause long-term damage to the neodymium magnets if the coating is damaged.

  • Gold-coating (Ni-Cu-Ni-Au)

Some Neodymium magnets are coated with gold to protect them from corrosion, oxidation, and rust, as it is one of the least reactive elements on the periodic table.

A layer of gold-plated nickel makes up this coating, which has a shiny metallic and is usually about 12 millionths of a meter thick.

However, there are a few disadvantages. The gold is costly and rubs off easily with frequent use. Consequently, exposing the neodymium magnets to moisture and oxygen.

  • Chrome (Ni-Cu-Ni-Cr)

Chrome is used to coat Neodymium magnets to prevent corrosion because it resists rubbing and pressure and is easy to apply. Besides, it also protects from oxidation and rusting.

Chrome coating has a dull, grey-metallic color and a thickness of approximately 15 micrometers.

Due to the above properties, Chrome coating is the best choice for sphere neodymium magnets.

  • Copper (Ni-Cu)

Copper (Ni-Cu) is also used to coat Neodymium magnets to prevent corrosion.

However, it has slightly lower rubbing, impact, and corrosion resistance than a nickel.

The thickness is 10 micrometers, and the color is shiny brown-red-gold. However, the color can change over time due to rust.

The copper-colored surface rubs off easily, just Like gold-coated neodymium magnets, so they’re only meant for decoration.

  • ABS Plastic

ABS Plastic can also be used for coating neodymium magnets because it can withstand high temperatures and is highly corrosion-resistant. This coating serves the aesthetic purpose as it is available in multiple colors.

The ABS plastic coating requires an injection mold to be created to encase the neodymium magnet. Moreover, the coating is usually thicker than other coatings to ensure plastic flows easily during injection molding.

  • Zinc

Zinc can also be used as a coating for neodymium magnets because it’s resistant to corrosion, which will help preserve the neodymium magnet’s integrity over time. Its self-sacrificing property creates a durable layer of protection around the neodymium magnets by oxidizing the outer layer of coating.

It also helps keep the neodymium magnet from attracting dirt or other particles that might otherwise interfere with its performance.

  • Teflon

Teflon is also used to coat neodymium magnets as it is durable, corrosion-resistant, resilient to the harsh environment, and protects the neodymium magnet from exposure to moisture and oxygen. Like ABS Plastic, Injection molding is also used for Teflon to encase the neodymium magnets.

Teflon is also because it has a low coefficient of friction, which means that it doesn’t stick to other materials very well. That makes it a good choice for coating neodymium magnets because it prevents them from sticking to other objects.

  • Rubber

The soft but stretchy quality of rubber makes it a good choice for coating neodymium magnets. That helps protect the neodymium magnets from being damaged, oxidized, corroded, and rusted and keeps them from sticking to each other.

  • Titanium

Titanium is used for coating neodymium magnets because it forms a tough skin that resists oxidization, rusting, corrosion, and scratching and chipping. It also has a low friction coefficient, which helps to reduce wear and tear on the neodymium magnet.

  • Tin (Sn)

The primary reason tin is used for coating neodymium magnets is its low oxidation rate. It also has a low melting point, making it a good conductor of electricity and corrosion-resistant.

Additionally, tin has a low “Coercivity,” meaning it can be easily demagnetized. This quality makes it ideal for use in coatings, as it allows the neodymium magnet’s full magnetic force to be achieved without any hindrance.

  • Titanium Nitride

The titanium nitride coatings improve the neodymium magnets’ resistance to oxidation, corrosion, and scratching, which can prolong their useful life.

  • Everlube

Everlube is a trademarked name for a range of lubricating and corrosion-resistant coatings. It is also known as dry film lubricants. It is often used to coat neodymium magnets because it protects them from corrosion and helps keep them running smoothly.

  • Polytetrafluoroethylene (PTFE)

PTFE, or Polytetrafluoroethylene, is a synthetic fluoropolymer used as a coating material because of its non-stick and low friction properties.

It is most commonly used in kitchenware (e.g., baking pans), cookware, and other household items.

PTFE has also been effective as a coating for neodymium magnets. It can help prevent the accumulation of corrosion and oxidation on the surface of the neodymium magnet.

Conclusion

Whether you’re looking to protect against corrosion or other types of wear, there are several ways to prevent your neodymium magnets from suffering.

While it’s almost impossible to avoid all contact with water while manufacturing and transporting these neodymium magnets, they can easily be kept safe and intact once applied with the best coating, depending on your application.

Suppose you are looking for High-Quality Neodymium Magnets that are adequately coated depending on your application and guarantee long protection against corrosion and rust. In that case, we suggest you try ROBO Magnetic(mail to sales@robomagnetic.com or contact us).

ROBO Magnetic is a leading manufacturer of neodymium magnets that have been operating for 16 years, and it produces an average of 800 tons of these powerful permanent magnets per year.

We have updated its production equipment and techniques to keep pace with the growing demands for its products.

Our polished equipment, solid techniques, and complete quality system make ROBO Magnetic one of the leading manufacturers in its field.

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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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