APLICACIONES DEL NEODIMIO EN EL MAGNETISMO (EN INGLES)

Neodymium Magnet Applications

Neodymium is a rare earth metal component mischmetal (mixed metal) which can be used to create powerful magnets. Neodymium magnets are the strongest known relative to their mass, with even small magnets able to support thousands of times their own weight. Although a “rare” earth metal, neodymium is widely available, leading to easily obtainable raw materials to manufacture neodymium magnets. Because of their strength, neodymium magnets are used in a broad range of applications, including jewelry, toys and computer equipment.

What Neodymium Magnets Are

Neodymium magnets, also known as NIB magnets, are measured from N24 to N55 on the magnetism scale that goes up to N64, which is a theoretical magnetism measurement. Depending on the shape, the composition, and the production method, NIB magnets can fall anywhere in this range and provide serious lifting strength.

In order to construct a neo, as they are sometimes also called, manufacturers collect rare earth metals and sift them to find usable neodymium, which they must separate from other minerals. This neodymium is ground up into a fine powder, which can then be resealed into a desired shape once combined with iron and boron. The official chemical designation of a neo is Nd₂Fe₁₄B. Due to the iron in a neo, it has properties similar to other ferromagnetic materials, including mechanical fragility. This can sometimes pose problems because the magnetic power is so great that if the neo connects too rapidly with a lot of momentum, it can chip or crack itself.


Neos are also susceptible to temperature differences and can crack or lose their magnetism in higher temperatures, usually above 176 degrees Fahrenheit. Some specialized neos work at higher temperatures, but generally above that level they fail to properly function. In cooler temperatures, neos will be fine. Because other types of magnets don’t lose their magnetism at these high temperatures, neos are often bypassed for applications that will be exposed to great amounts of heat.

Neodymium Magnet Applications

As neodymium magnets are so strong, their uses are versatile. They are produced for both commercial and industry needs. For example, something as simple as a piece of magnetic jewelry uses a neo to keep the earring in place. At the same time, neodymium magnets are being sent into space to help collect dust from the surface of Mars. Neodymium magnets’ dynamic capabilities have even lead to them being used in experimental levitation devices. In addition to these, neodymium magnets are used in such applications as welding clamps, oil filters, geocaching, mounting tools, costumes and many more.

Cautionary Procedures for Neodymium Magnets

Users of neodymium magnets must take caution when handling them. First, for everyday magnet use, it is important to monitor magnets that might be found by children. If a magnet is swallowed, it can block respiratory and digestive tracts. If more than one magnet is swallowed, they might connect and serious issues such as completely closing off the esophagus. The simple fact of having the magnet inside the body can lead ot infection as well.

Additionally, because of the extremely high magnetism of larger NIB magnets, they can literally fly across a room if ferromagnetic metals are present. Any body part caught in the path of a magnet hurtling towards an object, or an object hurtling towards a magnet, is in danger of serious danger if the pieces do fly around. Getting a finger trapped between a magnet and a table top can be enough to shatter the finger bone. And if the magnet connects to something with enough momentum and force, it can shatter, firing dangerous shrapnel that can puncture skin and bones in many directions. It is important to know what’s in your pockets and what type of equipment is present when handling these magnets.

Types of Magnets

Magnets are objects that generate a magnetic field, a force-field that either pulls or repels certain materials, such as nickel and iron. Of course, not all magnets are composed of the same elements, and thus can be broken down into categories based on their composition and source of magnetism. Permanent magnets are magnets retain their magnetism once magnetized. Temporary magnets arematerials magnets that perform like permanent magnets when in the presence of a magnetic field, but lose magnetism when not in a magnetic field. Electromagnets are wound coils of wire that function as magnets when an electrical current is passed through. By adjusting the strength and direction of the current, the strength of the magnet is also altered.

Permanent Magnets

There are typically four categories of permanent magnets: neodymium iron boron (NdFeB), samarium cobalt (SmCo), alnico, and ceramic or ferrite magnets.

• Neodymium Iron Boron (NdFeB)

This type of magnet is composed of rare earth magnetic material, and has a high coercive force. They have an extremely high energy product range, up to 50 MGOe. Because of this high product energy level, they can usually be manufactured to be small and compact in size. However, NdFeB magnets have low mechanical strength, tend to be brittle, and low corrosion-resistance if left uncoated. If treated with gold, iron, or nickel plating, they can be used in many applications. They are very strong magnets and are difficult to demagnetize.

• Samarium Cobalt (SmCo)

Like NdFeB magnets, SmCo magnets are also very strong and difficult to demagnetize. They are also highly oxidation-resistant and temperature resistant, withstanding temperatures up to 300 degrees Celsius. Two different groups of SmCo magnets exist, divided based on their product energy range. The first series (Sm1Co5) has an energy product range of 15-22 MGOe. The second series (Sm2Co17) has a range that falls between 22 and 30 MGOe. However, they can be expensive and have low-mechanical strength.

• Alnico

Alnico magnets get their name from the first two letters of each of three main ingredients: aluminum, nickel, and cobalt. Although they feature good temperature resistance, they can easily be demagnetized and are sometimes replaced by ceramic and rare earth magnets in certain applications. They can be produced by either sintering or casting, with each process yielding different magnet characteristics. Sintering produces enhanced mechanical traits. Casting results in higher energy products and enables the magnets to achieve more complicated design features.

• Ceramic or Ferrite

Comprised of sintered iron oxide and barium or strontium carbonate, ceramic (or ferrite) magnets are typically inexpensive and easily produced, either through sintering or pressing. However, because these magnets tend to be brittle, they require grinding using a diamond wheel. They are one of the most commonly used types of magnet, and are strong and is not easy to demagnetize.

Temporary Magnets

Temporary magnets can vary in composition, as they are essentially any material that behaves like a permanent magnet when in the presence of a magnetic field. Soft iron devices, such as paper clips, are often temporary magnets.

Electromagnets

Electromagnets are made by winding a wire into multiple loops around a core material—this formation is known as a solenoid. To magnetize electromagnets, an electrical current is passed through the solenoid to create a magnetic field. The field is strongest on the inside of the coil, and the strength of the field is proportionate to the number of loops and the strength of the current.

The material at the center of the coil, the core of the solenoid, can also affect the strength of an electromagnet. If a wire is wrapped around a nonmagnetic material, such as a piece of wood, the overall magnetic field will not be very strong. However, if the core is composed of ferromagnetic material, such as iron, the strength of the magnet will dramatically increase.

Applications

Within the industrial sector, magnets are often used as magnetic sweepers, sorters, and to separate impure metals during metal manufacturing or recycling. In electronic applications, magnets are used in speakers, televisions, telephones, radios, and videotapes. Typically, electromagnets are used within televisions, computers, and telephones because of their extreme strength. For this same reason, they are also used in on-off applications, such as cranes sued for heavy lifting.

Permanent magnets are perhaps the most common type—they are used to manufacture refrigerator magnets, as well as in jewelry making. Temporary magnets can be useful in applications that generate a temporary magnetic field and require a magnetic response for the duration of the field.