Neodymium Magnet Strength
neodymium magnet strength are among the strongest permanent magnets available commercially. They are made from an alloy of neodymium, iron, and boron (NdFeB). The strength of neodymium magnets is typically measured by their maximum energy product, which is a combination of their magnetic field strength and the volume of magnet material.
The maximum energy product (BHmax) for neodymium magnets can range from around 33 MGOe (mega-Gauss-oersteds) for lower grades to over 52 MGOe for the highest grades. MGOe stands for Mega-Gauss-Oersteds, a unit of magnetic energy product.
To put this in perspective, neodymium magnet strength are several times stronger than traditional magnets such as ferrite or alnico magnets. They have a wide range of applications, from consumer electronics to industrial machinery, due to their exceptional strength-to-size ratio.
1.マグネティック
Experiments show that any substance can be magnetized to a greater or lesser extent in an external magnetic field, but the degree of magnetization is different. According to the characteristics of substances in external magnetic fields, substances can be divided into five categories: paramagnetic substances neodymium magnet strength, diamagnetic substances, ferromagnetic substances, ferrimagnetic substances, and antiferromagnetic substances. We call paramagnetic substances and diamagnetic substances weak magnetic substances, and ferromagnetic substances and ferrimagnetic substances are called strong magnetic substances.
2.磁性材料
Soft magnetic material: It is a magnetic material with low coercive force and high magnetic permeability that can achieve the maximum magnetization intensity with the smallest external magnetic field. Soft magnetic materials are easy to magnetize and demagnetize neodymium magnet strength. For example: soft ferrite, amorphous nanocrystalline alloy.Hard magnetic materials: also called permanent magnet materials, are materials that are difficult to magnetize and are difficult to demagnetize once magnetized. Their main feature is high coercive force, including rare earth permanent magnet materials, metal permanent magnet materials and permanent ferrite magnets. .
機能性磁性材料：主に磁歪材料、磁気記録材料、磁気抵抗材料、磁気バブル材料、磁気光学材料、磁性フィルム材料などが含まれる。
3.NdFeB永久磁石材料
The sintered NdFeB permanent magnet material uses a powder metallurgy process. The smelted alloy is made into powder and pressed into a compact in a magnetic field neodymium magnet strength. The compact is sintered in an inert gas or vacuum to achieve densification. In order to improve the coercive force of the magnet , usually requires aging heat treatment, and then post-processing and surface treatment to obtain the finished product.
Bonded NdFeB is made of permanent magnet powder mixed with bonding materials such as rubber with good windability or hard and light plastics and rubber neodymium magnet strength, and is directly formed into permanent magnet components of various shapes according to user requirements.
ホットプレスNdFeBは、重希土類元素を添加することなく、焼結NdFeBと同様の磁気特性を得ることができる。高密度、高配向性、良好な耐食性、高保磁力、ニアネットシェイプを有する。利点はあるが、特許独占のため機械的特性が悪く、加工コストが高い。
4.レマネンスBr
磁石を閉回路環境で外部磁界により技術的に飽和するまで磁化し、その後外部磁界を除去したときに、焼結ネオジム磁石が示す磁気誘導強度を指す。平たく言えば、着磁後の磁石の磁力と一時的に理解できる。単位はテスラ（T）とガウス（Gs）で、1Gs=0.0001T。
5.強制力 Hcb
When the magnet is reversely magnetized, the value of the reverse magnetic field intensity required to reduce the magnetic induction intensity to zero is called the magnetic induction coercivity neodymium magnet strength. However, the magnetization intensity of the magnet is not zero at this time, but the applied reverse magnetic field and the magnetization intensity of the magnet cancel each other out. If the external magnetic field is removed at this time, the magnet still has certain magnetic properties. The unit is Oersted (Oe) or A/m (A/m), 1A/m=79.6Oe.
6.固有保磁力Hcj
The strength of the reverse magnetic field required to reduce the magnetization of a magnet to zero is called the intrinsic coercive force neodymium magnet strength. The classification of magnetic material grades is based on the size of their intrinsic coercive force. Low coercivity N, medium coercivity M, high coercivity H, ultra high coercivity UH, extremely high coercivity EH, and highest coercivity TH.
7.最大磁気エネルギー積(BH)max
It represents the magnetic energy density established in the two magnetic pole spaces of the magnet, that is, the static magnetic energy per unit volume of the air gap. It is the maximum value of the product of Br and Hcj neodymium magnet strength. Its size directly indicates the performance of the magnet. Under the same conditions, that is, the same size, the same number of poles and the same magnetizing voltage, magnetic parts with high magnetic energy products also have high surface magnetism, but at the same (BH)max value, the level of Br and Hcj It has the following effects on magnetization:
高Br、低Hcj：同じ着磁電圧で、より高い表面磁性が得られる；
低Br、高Hcj：同じ表面磁性を得るためには、より高い着磁電圧が必要。
8.SIシステムとCGSシステム
つまり、国際単位系とガウス単位系は、長さの単位における「メートル」と「マイル」の違いのようなものである。国際単位系とガウス単位系の間には、ある複雑な換算関係がある。
9.キュリー温度
It is the temperature at which magnetic materials change between ferromagnets and paramagnets. When the material is lower than the Curie temperature, it becomes a ferromagnet neodymium magnet strength. At this time, the magnetic field related to the material is difficult to change. When the temperature is higher than the Curie temperature, the material becomes a paramagnet, and the magnetic field of the magnet changes easily with changes in the surrounding magnetic field.
The Curie temperature represents the theoretical operating temperature limit of magnetic materials. The Curie temperature of NdFeB is about 320-380 degrees Celsius. The level of the Curie point is related to the crystal structure formed by the sintering of the magnet. If the temperature reaches the Curie temperature neodymium magnet strength, the molecules inside the magnet will move violently and demagnetize, which is irreversible. The magnet can be magnetized again after demagnetization, but the magnetic force will drop significantly and can only reach about 50% of the original value.
10.動作温度
焼結 NdFeB の最高使用温度は、キュリー温度よりはるかに低い。動作温度内で温度が上昇すると、磁力は低下するが、冷却後に磁力の大部分は回復する。
The relationship between working temperature and Curie temperature: the higher the Curie temperature, the higher the working temperature of magnetic materials, and the better the temperature stability neodymium magnet strength. Adding elements such as cobalt, terbium, and dysprosium to sintered NdFeB raw materials can increase its Curie temperature. Therefore, high coercivity products (H, SH,…) generally contain added dysprosium.
The maximum operating temperature of sintered NdFeB depends on its own magnetic properties and the selection of the working point. For the same sintered NdFeB magnet, the closer the working magnetic circuit is neodymium magnet strength, the higher the maximum operating temperature of the magnet is, and the more stable the performance of the magnet is. Therefore, the maximum operating temperature of the magnet is not a definite value, but changes with the degree of closure of the magnetic circuit.
11.磁場の向き
Magnetic materials are divided into two categories: isotropic magnets and anisotropic magnets. The magnetic properties of isotropic magnets are the same in any direction and can be attracted together at will; the magnetic properties of anisotropic magnets will be different in different directions neodymium magnet strength. The direction in which it can obtain the best magnetic properties is called the orientation direction of the magnet.
For a square sintered NdFeB magnet, only the orientation direction has the largest magnetic field intensity, and the other two directions have much smaller magnetic field intensity. If the magnetic material has an orientation process during the production process, it is an anisotropic magnet. Sintered NdFeB is generally molded and pressed with magnetic field orientation, so it is anisotropic. Therefore, it is necessary to determine the orientation direction before production, that is, the future magnetization direction. . Powder magnetic field orientation is one of the key technologies for manufacturing high-performance NdFeB. (Bonded NdFeB can be either isotropic or anisotropic)
12.表面磁性
It refers to the magnetic induction intensity at a certain point on the surface of the magnet (the surface magnetism at the center and edge of the magnet is different). It is a value measured by the contact between a gaussmeter and a certain surface of the magnet, not the overall magnetic performance of the neodymium magnet strength.
13.磁束
Assume that in a uniform magnetic field with a magnetic induction intensity B, there is a plane with an area S and perpendicular to the direction of the magnetic field. The product of the magnetic induction intensity B and the area S is called the magnetic flux passing through this plane, referred to as magnetic flux, symbol “Φ” , the unit is Weber (Wb). Magnetic flux is a physical quantity that represents the distribution of a magnetic field. It is a scalar quantity, but it has positive and negative values. The positive and negative values only represent its direction. Φ=B·S, when there is an angle θ between the vertical plane of S and B, Φ=B·S·cosθ.
14.電気メッキ
Sintered NdFeB permanent magnet material is produced by powder metallurgy process. It is a very chemically active powder material. There are tiny pores and cavities inside, which are easily corroded and oxidized in the air neodymium magnet strength. Therefore, strict surface treatment must be carried out before use. As a mature metal surface treatment method, electroplating is widely used.
The most commonly used coatings for NdFeB powerful magnets are zinc plating and nickel plating. They have obvious differences in appearance, corrosion resistance, service life, price, etc.:
Difference in polishability: Nickel plating is superior to zinc plating in terms of polishing, and the appearance is brighter. Those with high requirements on product appearance generally choose nickel plating neodymium magnet strength, while some magnets are not exposed, and those with relatively lower requirements on product appearance are generally galvanized.
Difference in corrosion resistance: Zinc is an active metal and can react with acids, so its corrosion resistance is poor; after nickel plating surface treatment, its corrosion resistance is higher.
Difference in service life: Due to different corrosion resistance, the service life of zinc plating is lower than that of nickel plating. This is mainly reflected in the fact that the surface coating easily falls off after being used for a long time neodymium magnet strength, causing the magnet to oxidize, thus affecting the magnetic performance.
Difference in hardness: Nickel plating is higher than zinc plating. During use, it can greatly avoid collisions and other situations, causing the NdFeB powerful magnets to fall off corners and break.
価格差：この点では亜鉛メッキが極めて有利。価格の安いものから高いものまで、亜鉛メッキ、ニッケルメッキ、エポキシ樹脂など。
15.片面マグネット
Magnets have two poles, but in some working positions, single-sided magnets are required, so one side of the magnet needs to be wrapped with an iron sheet so that the magnetism of the side covered by the iron sheet is shielded neodymium magnet strength. Such magnets are collectively called single-sided magnets. Or a single sided magnet. There is no such thing as a true single-sided magnet.
