Dailymag Magnetics is a professional Magnets Manufacturer. We specialize in R&D and fabrication of Sintered NdFeB Magnets and Permanent Magnets.
SINTERED NDFEB MAGNETS INFORMATION
Overview: Sintered NdFeB Magnets
Sintered NdFeB magnets (also known as "neo" magnets) are among the most popular magnets in the market today. The magnets have been available commercially since November 1984. They boast of offering the highest energy product (of any material/magnets today) and are available in a wide variety of sizes, grades and shapes (discs, arcs, blocks, spheres, trapezoid etc.).
Initially, NdFeB magnets were primarily used for making VCM’s (voice coil motors) in hard disk drives. This application still accounts for approximately 55 percent of all total sales of Sintered NdFeB magnets today. The magnets have many other applications due to their reasonable cost and superior magnetic properties. NdFeB magnets are used in making many tools/equipment such as communication tools, computer devices, motors, sensors, speakers and medical treatment instruments just to mention a few tools/equipment.
Sintered NdFeB magnets are made using an intermetallic compound; Nd2Fe14B which is composed of 2 rare earth atoms, one boron atom and 14 iron atoms. Besides the main-phase Nd2Fe14B (in NdFeB materials), there are some small quantities of rare Nd-rich phase (earth-rich phase), boron-rich phase and others. The earth-rich phase pins domain walls to give sintered NdFeB magnets a high coercive force. NdFeB magnets available today commercially have numerous partial alloying Nd and Fe substitution combinations which results in a variety of properties. Moreover, the magnets majorities are anisotropic which simply means they are capable of being magnetized in the orientation direction. Neo magnets are 3rd generation rare earth magnets which are simply the most commercially advanced and powerful magnets in the market today.
Sintered NdFeB magnets emit very deep magnetic fields attracting other magnets and ferrous items from impressive distances. The magnets are extremely strong when you consider factors like size. The magnets are a true representation of what small powerful magnets can do. Small Sintered NdFeB magnets have an unmatched amount of magnetic force. For instance, the magnets are capable of lifting magnets/metals weighing 1,000 times (their own weight).
You are bound to be amazed at the strength of Sintered NdFeb magnets if you haven’t handled neodymium magnets before. The magnets are 10 times stronger than ferrite magnets which are the strongest ceramic magnets. Another notable advantage of the magnets lies in the fact that they come in a variety of shapes the most common being block, ring and disc shapes. It’s also possible to have custom shapes. The magnets have other advantages i.e. their excellent coercive force, high remanences as well as brilliant high energy product.
Although Neo magnets have numerous advantages, they have a couple of limitations as well. First and foremost, the magnets are susceptible to corrosion. It is however important to note that a protective coating is adequate enough to deal with this problem effectively. In most cases, Sintered NdFeB magnets are coated using a NiCuNi (Nickel-Copper-Nickel) triple layer plating, dry electrostatic spray epoxy and zinc coating.
Sintered NdFeB magnets also have a large density which makes them extremely fragile. The magnets must therefore be used cautiously.
Sintered NdFeB magnets also tend to lose their magnetism fast when exposed to high operating temperatures exceeding the max. Operating temperature rating of 230C. It is however worth noting that numerous changes in the composition as well as processing of Sintered NdFeB magnets over the past few years has resulted in a massive improvement of the magnets' high temperature performance as well as corrosion resistance.