ferrite magnets
Application of advanced soft magnetic materials in the motor industry
Oct 11,2021.

In the last few decades, the demand for new magnetic materials in the automobile and other industries has surged. In the mid-1990s, the first parts made of soft magnetic composite materials were born. The use of these soft magnetic composite materials (SMC) The trend has continued to grow. The first soft magnetic material parts are ignition cores for automobiles, which are widely used in most general vehicles. They are compacted into a round shape, and no insulating tape is used to protect the primary winding from the coil. Today, powder metal and soft magnetic composite material technology has come a long way, and it provides technological changes that did not exist before. The correct soft magnetic material makes the motor flux transmission faster, consumes less energy, and the motor structure becomes more compact. The motor can use higher frequency, denser electromagnetic, high penetration, and greatly reduce the eddy current loss of the rotor/stator.

Electric motors use direct current (DC) stored in batteries or alternating current (AC) from generators and power grids to convert electrical energy into mechanical energy. They can be used in electric vehicles, small household appliances, industrial fans and pumps, machine tools, and large ships and aircraft for propulsion. Continued research on soft magnetic composite materials (SMC) has shown that they have great potential in DC and AC applications, by allowing engineers to develop new innovative designs that improve the magnetic induction of core materials at low and medium frequencies. Soft magnetic materials are composed of electrically insulating ferromagnetic powders. When optimizing particle size, shape and microstructure, they have many valuable advantages, including magnetic and thermal isotropy, high permeability, low coercivity, and Curie High temperature and low total iron loss.

"Soft" means that in the sense of magnetism, the term has nothing to do with the hardness of the material. Soft magnetic materials are easy to magnetize and demagnetize. Permanent, or "hard" magnets always maintain their magnetization. The soft magnetic composite material is made of iron powder particles with high purity and compressibility and thin and uniform laminates bonded together. The coating provides high resistivity, insulates the edges of each individual particle, and limits the generation of eddy currents. Soft magnetic composites are ferromagnetic powder particles ideally coated with a uniform electrically insulating film, just like any other powdered metal part. Soft magnetic composite materials are compacted using heated molds to promote higher density, permeability, and inductivity. The soft magnetic composite material depends on the final application, and the magnetic properties are affected by various corresponding parameters, including the alloy material used, the density of the final part (saturation sensitivity and permeability are affected by the density), the sintering temperature, the carbon and nitrogen content after sintering .

Powder metal magnetic materials can be classified as sintered (for DC or DC applications) or soft magnetic composite types (for AC or AC applications). Compared with sintered materials, the advantage of soft magnetic composites is that their design has competitive magnetic properties. , Has a higher resistivity. Resistivity makes soft magnetic materials attractive to those who are manufacturing low-loss parts (especially high-frequency parts) an important reason. The advantage of soft magnetic materials lies in the molding ability of powders. The use of soft magnetic powders can easily realize shapes usually made of powdered metal, can achieve 3D magnetic flux carrying capacity, and can efficiently complete complex 3D geometric shapes. They are between powder particles. There will be no metallurgical bond. Instead, rely on the strength of the interlocking particles plus the strength provided by the insulating layer.

Heat treatment of soft magnetic materials may affect the magnetic properties. The focus of heat treatment is twofold: to improve soft magnetic properties (reducing stress) to improve mechanical properties, heat treatment or curing is not sintered, and no metallurgical bond is formed. The higher the temperature, the better the strength of the soft magnetic material. The nature of powder metallurgy can use a smaller motor design to reduce material consumption, or obtain higher power from a similar size to the current motor, which opens up for electromagnetic equipment A huge market. These components can bridge the frequency limitations of traditional laminated steel cores, especially the gap between ferrite cores of a few hundred hertz and a few megahertz. The soft magnetic material can completely eliminate the motor failure/overheating caused by the accumulation of eddy current caused by the poor insulation of the ferromagnetic layer.

In conclusion

Magnetic composite materials can realize the revolutionary design of electromagnetic equipment to help improve efficiency, reduce weight and cost, without affecting magnetic performance. The electrically insulating metal particles are made into the stator or rotor of the motor, and their loss and permeability are tested to minimize and maximize them respectively. Soft magnetic powder has shown the greatest potential as a core material, with the high electrical resistance of nanocrystalline materials, and the advantages of very low coercivity of amorphous materials. Similarly, organic and inorganic coating materials have been explored to reduce eddy currents to improve the overall core material loss at higher frequencies. In soft magnetic material applications, the balance between performance is the most important.

Request a free quote
If you are interested in our products and want to know more details,please leave a message here,we will reply you as soon as we can.
Leave a message
welcome to BearHeart
If you are interested in our products and want to know more details,please leave a message here,we will reply you as soon as we can.