Magnet Knowledge

1.How to order a magnet?

In order to enable us to more effectively cooperate with your work, we need you to confirm the following before placing an order:

(1). What is the material and performance?

(2).What is the size and tolerance?

(3). Which magnetized direction you need? Axial, diametrical?

(4). The maximum temperature of the magnet working environment?

(5). Your purchase quantity?

(6).Surface treatment? NiCuNi, zinc, epoxy coating?

(7). What is the shape of the magnet?

(8). For special handling, please inform us.

Magnet Knowledge 2 What are the applications of NdFeB magnets?
NdFeB permanent magnet with its excellent performance, rich raw materials, reasonable prices are being rapid development and wide range of applications. It is mainly used in micro motor, permanent magnet instrument, electronic industry, automobile industry, petrochemical, nuclear magnetic resonance device, sensor, audio equipment, magnetic levitation system, magnetic drive mechanism and magnetic therapy equipment and so on.

Magnet Knowledge 3.Comparison of magnetic materials
Ferrite performance is low, the lowest price, good temperature characteristics, corrosion resistance.
NdFeB performance is highest, the price is relatively high, good strength, do not have high temperature and corrosion
SmCo high performance, the highest price, brittle, excellent temperature characteristics, corrosion resistance
Alnico low performance, medium price, excellent temperature characteristics, corrosion resistance, poor resistance to interference
SmCo, ferrite, neodymium iron boron can be sintered and bonded manufacturing method, sintered high magnetic properties, poor molding, bonded magnet shape is good, the performance is much lower.
AlNiCo can be manufactured by casting and sintering methods. Casting magnets have high performance, poor formability, low sintered magnets and good formability.

Magnet Knowledge

Magnet Knowledge

Magnet Knowledge 4 NdFeB consists of those materials?
The main raw materials of NdFeB permanent magnet are rare earth metal neodymium (Nd) 32%, metal element iron (Fe) 64% and non-metallic element boron (B) 1% (small addition of dysprosium (Dy), terbium (Tb), cobalt (Co), niobium (Nb), gallium (Ga), aluminum (Al), copper (Cu) and other elements). NdFeB ternary system permanent magnet material is Nd2Fe14B compound as a matrix, its composition should be similar to the compound Nd2Fe14B molecular formula. But completely according to Nd2Fe14B composition ratio, the magnetic properties of the magnet is very low, even non-magnetic. Only the actual magnet which neodymium and boron content than Nd2Fe14B compounds neodymium and boron content in order to get better permanent magnetic properties.

Magnet Knowledge 5 NdFeB magnetic properties can last long?
NdFeB magnets have a very high coercive force, natural environment and general magnetic field conditions will not appear demagnetization and magnetic changes. Assuming that the environment is appropriate, even after prolonged use, the magnetic properties of the magnets are not very large. So in practical applications, we often ignore the time factor on the magnetic properties.

Magnet Knowledge 6 About orientation:
Orientation direction: Anisotropic magnet can obtain the best magnetic properties of the direction of the magnet is called the direction of orientation. Magnet is divided into:
(1). Isotropic magnet: Magnet with the same magnetic properties in any direction
(2). Anisotropic magnets: magnetic properties in different directions will be different; and there is a direction that the orientation direction, in the direction of the magnetic properties obtained when the highest magnet. Sintered NdFeB permanent magnets are anisotropic magnets, and thus need to determine the direction of orientation (magnetization direction) before production.

Magnet Knowledge 7 Factors that affect the magnetism of NdFeB magnets?
Ambient temperature, due to the extremely sensitive to the working temperature of the sintered NdFeB Magnet, the maximum temperature and the maximum temperature of the environment may cause different degrees of demagnetization of the magnet, including reversible and irreversible, recoverable and irreversible.

Magnet Knowledge 8 What is the working temperature range of NdFeB magnets?
The temperature limit of the NdFeB magnets raises a series of grades of magnetsto suit different operating temperature requirements, please refer to our performance catalog for comparison of the grade magnet operating temperature range. It is necessary to confirm the maximum operating temperature before selecting NdFeB magnets.

Magnet Knowledge 9 how to shield the magnetic field?
Generally we use ordinary iron shield magnetic field. Magnetic shielding requires a high permeability material, and the material that meets this requirement is an iron-nickel alloy, which has a high permeability. When the need to shield the magnetic field is very strong, only a single layer of shielding material, not reach the shielding requirements, that is, saturation occurs. At this point, one way is to increase the thickness of the material. But a more efficient way is to use a combination of shielding, a shield placed in another shield, leaving an air gap between them. The air gap can be filled with any non-magnetic material to support such as aluminum. The shielding effectiveness of the combined shield is much higher than that of a single shield, so the combined shield can attenuate the magnetic field to a very low level.

Magnet Knowledge 10 What are the precautions for the storage and transportation of magnets?
Magnet in the storage to keep the indoor ventilation and dry, otherwise the wet environment easy to make the magnet rust. The ambient temperature should not exceed the maximum working temperature of the magnet; the product of the unplated product can be properly coated with oil rust; the magnetized product should be kept away from the magnetic field, magnetic card, tape, computer monitor, watch and so on. Magnet material is more brittle, transport, plating (coating), the installation process, should ensure that the magnets from severe impact, if the method is not appropriate, may cause magnetic damage, crack; magnet magnetization state of transport should be shielded, Transport must be completely shielded.

Magnet Knowledge 11 What are the precautions for the operation of the magnet?
Magnet in the course of the work should ensure that the workplace clean, or easy to absorb iron and other magnetic particles affect the use of small particles; NdFeB material is characterized by hard and brittle, and its suction up to its own weight of more than 600 times, Damage. The operation process for small size should pay attention to avoid bump damage, for large size should pay attention to personal safety and protection.

Magnet Knowledge 12 What is the cause of the coating skinning and get rusty?
Qualified electroplating products, under normal circumstances, plating plating should not appear rust. In the too wet, air flow is not good, the temperature difference is large, even if the salt spray test qualified products stored in the harsh environment for a long time may produce rust. When the plating products stored in the environment harsh environment, the base layer and further reaction with the condensate, will cause the base layer and the coating of the binding force is reduced, serious will also cause the base of local powder, and then naturally from the skin. Electroplating products should not be placed in high humidity for a long time and should be placed in a cool, dry place.

Magnet Knowledge 13 how to measure the level of magnetic properties?
There are three main parameters: residual magnet Br (Residual Induction), the unit Gauss, from the saturation state to remove the magnetic field, the remaining magnetic flux density, represents the magnet can provide magnetic field strength; coercivity Hc (Coercive Force), unit Oersteds, is to put the magnet in a reverse magnetic field, when the external magnetic field increases to a certain strength when the magnet magnetism will disappear, the ability to resist the external magnetic field called coercivity, represents the ability to measure anti-demagnetization; Product BHmax, the unit Gauss-Oersteds, is the unit volume of material produced by the magnetic field energy, the magnet can store the amount of energy a physical quantity.

Magnet Knowledge 14 commonly used magnetic measuring instruments
Commonly used magnetic measuring instruments are: magnetic flux meter, Tesla meter (also known as Gauss meter), magnetic measuring instrument. The flux gauge is used to measure the magnetic flux. The Tesla meter is used to measure the surface magnetic field strength or air gap magnetic field strength. The magnetic tester is used to measure the comprehensive magnetic properties. All instruments should be read carefully before using the instructions, according to the requirements of the preheating, preheating in accordance with the requirements of the instructions to operate.

Magnet Knowledge 15 How to manufacture NdFeB Magnet?
Sintered NdFeB permanent magnet is an iron-based permanent magnet material made by powder metallurgy process. The main processes are: formula, smelting, milling, molding orientation, sintering, machining, electroplating and so on. The control of oxygen content is an important measure of the level of technology. I produced the device used in the high vacuum melting, sintering furnace and advanced automatic control of the air mill to ensure that the basic production process without oxygen, so that the performance of products and the use of temperature have a breakthrough to improve.

6 The factors that affect the magnet processing costs?
The machining costs of magnets are mainly affected by the following factors: performance requirements, bulk size, gauge shape, tolerance dimensions. The higher the cost, the higher the cost, such as the price of N52 magnet is much higher than the N35 Magnet price; the smaller the batch, the higher the processing cost; the more complex the shape, the higher the processing cost; the more stringent tolerances, the higher the processing cost.

17 About rare earth permanent magnet materials
The rare earth permanent magnet material is a kind of magnetic material prepared by sintering the rare earth permanent magnet alloy composed of samarium, neodymium mixed rare earth metal and transition metal, sintered by powder metallurgy method and magnetized by magnetic field.
Rare earth permanent magnet material as a high performance functional materials, is widely used in energy, transportation, machinery, medical, IT, home appliances and other fields, has become the basis of many high-tech industries. The NdFeB rare earth permanent magnetic materials because of a high cost performance, as the fastest growing, the highest degree of industrialization of the industry.