Anisotropic (II)

 

 

 Magnet

Demagnetization Curve

The second quadrant of the hysteresis loop, generally describing the behavior of magnetic characteristics in actual use. Also known as the B-H Curve.

Dimensions

The physical size of a magnet including any plating or coating.

Dimensional Tolerance

An allowance, given as a permissible range, in the nominal dimensions of a finished magnet. The purpose of a tolerance is to specify the allowed leeway for variations in manufacturing.

Hysteresis Loop

A plot of magnetizing force versus resultant polarisation (also called a J/H curve) or magnetizing field versus of the material as it is successively magnetized to saturation, demagnetized, magnetized in the opposite direction and finally remagnetized. With continued recycles, this plot will be a closed loop which completely describes the characteristics of the magnetic material. The size and shape of this “loop” is important for both hard and soft materials. The first quadrant of the loop (that is +X and +Y) is called the magnetization curve. It is of interest because it shows how much magnetizing force must be applied to saturate a magnet. The second quadrant (-X and +Y) is called the Demagnetization Curve.

Induction (B) magnet

The magnetic flux per unit area of a section normal to the direction of flux.

Intrinsic Coercive Field (H_ci)

Indicates a materials’ resistance to demagnetization. It is equal to the demagnetizing field which reduces the intrinsic induction, Bi, in the material to zero after magnetizing to saturation.

Irreversible Losses

Partial demagnetization of the magnet, caused by exposure to high or low temperatures, external fields, shock, vibration, or other factors. These losses are only recoverable by remagnetization. Magnets can be stabilized against irreversible losses by partial demagnetization induced by temperature cycles or by external magnetic fields.

Isotropic Material

A material that can be magnetized along any axis or direction (a magnetically unoriented material). The opposite of Anisotropic Magnet.

Magnet

A magnet is an object made of certain materials which creates a magnetic field. Every magnet has at least one north pole and one south pole. By convention, we say that the magnetic field lines leave the North end of a magnet and enter the South end of a magnet. This is an example of a magnetic dipole (“di” means two, thus two poles).

Material Grade

Neodymium (NdFeB) magnets are graded by the magnetic material from which they are manufactured. Generally speaking, the higher the grade of material, the stronger the magnet.Neodymium magnets currently range in grade from N35 to N52.

Maximum Energy Product (BHmax) 

The magnetic field strength at the point of maximum energy product of a magnetic material.

Maximum Operating Temperature (Tmax) 

Also known as maximum service temperature, is the temperature at which the magnet may be exposed to continuously with no significant long-range instability or structural changes.

Magnetization Curve

The first quadrant portion of the hysteresis loop (B/H) Curve for a magnetic material.

Orientation

Used to describe the direction of magnetization of a material. Orientation Direction – The direction in which an anisotropic magnet should be magnetized in order to achieve optimum magnetic properties.

Permanent Magnet

A magnet that retains its magnetism after it is removed from a magnetic field. A permanent magnet is “always on”. Neodymium magnets are permanent magnets.

Temperature Coefficient   

A factor that is used to calculate the decrease in magnetic flux corresponding to an increase in operating temperature. The loss in magnetic flux is recovered when the operating temperature is decreased.


Post time: Dec-28-2020
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