Here is a list of 14 Magnetic Materials categories. It encompasses a wide range including permalloy, ferrite cores, ferrites, ferrite magnets, etc. You can search for an overview, principle, and usage of each category, as well as find manufacturers and distributors.
Magnetic materials are materials that utilize their strong magnetism to perform various functions.
Magnetic materials can be broadly classified into two types. One is a magnet attached to a metal such as iron, which is a hard magnetic material. The other is a type of material that becomes a magnet when a magnetic field is applied to it, but is no longer a magnet when the magnetic field is removed, and is a soft magnetic material.
Hard magnetic materials do not start out as magnets, but become magnets when they are magnetized by applying a momentary magnetic field. It is also possible to lose magnetism by applying an alternating magnetic field or by raising the temperature above the Curie temperature (Tc) to make the spontaneous magnetization zero, which is called demagnetization.
The residual flux density (Br [T]) of a magnet is the magnetic force it exhibits when the magnetic field is removed. On the other hand, soft magnetic materials show almost no magnetic force after the magnetic field is removed, and Br is close to zero.
The difference between hard and soft materials is not a difference in the physical hardness of the materials, but a difference similar to that between a hard and soft head in the sense of whether the material is amenable to the environment or not.
Both hard and soft magnetic materials are classified as ferromagnetic, and the specific magnetic permeability, which expresses how easily a material is magnetized, is much higher than 1. The term magnetic material refers to ferromagnetic materials. In contrast to ferromagnetic materials, there are also paramagnetic and antimagnetic materials, which have a specific permeability of around 1 and are hardly magnetized.
The BH curve is a typical representation of the characteristics of magnetic materials. It is a curve that depicts the magnetic field H [A/m] on the horizontal axis and the magnetic flux density B [T] on the vertical axis when the magnetic field given to magnetic materials is varied. The intercept between the curve and the abscissa is called the residual flux density (Br).
Depending on the altitude of the magnetic metal, it can be broadly classified into hard magnetic materials, soft magnetic materials, and magnetostrictive materials. Major applications include home appliances, motors, generators, magnetic disks, and everything from the home to the manufacturing floor. Since the performance of magnetic materials varies greatly depending on the environment and physical conditions, it is necessary to select the most suitable magnetic materials for the environment in which they will be used.
Soft magnetic materials include iron, silicon iron, permalloy, soft ferrite, sendust, permendur, electromagnetic stainless steel, amorphous, and nanocrystalline.
Hard magnetic materials include hard ferrites, alnico magnets, samarium-cobalt magnets, neodymium magnets, and samarium-iron-nitrogen magnets. Ferrite is a magnetic material consisting mainly of iron oxide mixed with barium, strontium, cobalt, nickel, manganese, etc., and sintered at 1,000 to 1,400 ºC.
Typical examples are as follows:
Rare earth magnetic materials are magnetic materials used mainly in automotive parts, motors and electronic devices. In particular, neodymium-iron magnetic materials are hard, durable, and have a very large magnetic energy product.
However, these magnetic materials tend to lose their magnetism at high temperatures, so particular attention should be paid to the thermal environment in which they are used. Samarium-cobalt magnets, which are also rare earth magnets, have slightly less magnetic force than neodymium magnets, but they have great durability against heat and rust, so they can be used under high temperatures where neodymium materials are not suitable.
Alnico magnetic materials are cast materials made primarily of aluminum, nickel, and cobalt. This material is resistant to temperature, and its hardness and strength make it difficult to crack, and it is mainly used in instruments and other devices. However, its coercive force is lower than that of other materials, so it easily loses its magnetic force due to external shocks.
Ferrite magnets are mainly made of powdered iron oxides and are extremely versatile magnetic materials. Applications include small motors, speakers, magnetic tapes, etc. Since it is relatively inexpensive for its high coercive force, it is used in products for mass production. Since it is manufactured from powder, it is brittle against impact and is not suitable for cutting or drilling.
Hard magnetic materials are used in motors, speakers, and headphones. Soft magnetic materials are used in solenoid valves, various sensors, televisions, videos, and personal computers.
The two major property categories of magnetic materials are isotropic and anisotropic. These properties depend on whether a magnetic field is applied or not during the process of making magnetic materials, and anisotropic magnetic materials retain a stronger magnetic force.
*This ranking is solely among the companies registered with Metoree, sorted by the number of employees. Please use this as a rough guide to understand their scale.