Development Trends of  Lamination Materials For Driven Electric Motors

With the rapid development of new energy vehicles, there is an increasing demand for higher efficiency and performance in electric motors.  This blog explores the requirements and development trends of lamination materials for driven electric motors, focusing on various high-performance materials available in the market.

In motor design, iron core materials play a crucial role, as high-performance core materials can enhance motor performance and efficiency, leading to reduced energy consumption and noise.

applications in electric vehicles

6.5%Si High-Silicon Steel

6.5%Si high-silicon steel is a special type of electrical steel with a silicon content as high as 6.5%. It exhibits excellent magnetic properties, making it an ideal core material for low-noise, reliability, and durability transformers, reactors, and high-frequency motors.

However, the brittleness of this material and the challenges in conventional processing methods limit its production and application. Currently, only Japan’s JFE company has achieved industrial production of 6.5%Si high-silicon steel using the chemical vapor deposition (CVD) method.

electrical steel

Cobalt-iron (CoFe) Alloy

CoFe alloy is a cobalt-iron alloy known for its high cobalt content, making it one of the most expensive alloys. When alloyed with iron, CoFe reaches the highest saturation magnetization intensity at room temperature among all materials.

It finds applications in aircraft electric motors, oilfield (“downhole”) motors, generators, and specialized electric and hybrid power systems in racing, among other uses.

Due to its high strength, CoFe steel can be used in high-speed rotor lamination cores, such as magnetic bearings, flywheel energy storage systems, and high-speed generators.

Nickel-Iron (NiFe) Alloy

NiFe alloy, composed of nickel and iron with additional impurities like Cr, Si, S, P, and C, boasts extremely low coercive force compared to CoFe and SiFe materials, along with a higher relative permeability. However, it has lower saturation and maximum magnetic flux density.

NiFe alloys with approximately 45%-50% nickel are commonly used in motors with low-loss requirements, such as dental and surgical instruments operating within tight thermal constraints, low-loss aerospace applications, and non-motion devices like resolvers.

Amorphous Alloy

Amorphous metal alloy, a new type of soft magnetic material made from amorphous ribbon, exhibits characteristics such as high magnetic permeability, high resistivity, low loss, and low coercivity. It is widely used in energy-efficient distribution transformers and amorphous motor laminations

While applying amorphous alloy materials used in motor cores can significantly reduce core losses and improve motor efficiency, challenges include its low saturation magnetic density compared to traditional silicon steel.

Additionally, amorphous alloy materials are thin, brittle, and hard, making them sensitive to cutting and stacking laminations, and winding coils manufacturing processes.

Soft Magnetic Composite (SMC) Materials

Soft magnetic composite materials disperse magnetic particles uniformly in non-magnetic substances, reducing high-frequency eddy current losses and improving application frequency. They can be processed into powder cores using hot pressing or injection molded into complex shapes using plastic engineering techniques.

SMC materials for motor laminations offer advantages such as low density, lightweight, high production efficiency, low cost, and good product repeatability and consistency. Currently, they can be used as axial flux motor stator materials.

In automotive motor applications, there is a growing demand for core materials with lower iron losses, higher magnetic sensitivity, and increased mechanical strength.

As motor speeds increase, the frequency of core material usage also rises, resulting in a significant increase in iron losses at high frequencies. Thinning the core material reduces iron losses, making thin-gauge non-oriented silicon steel a trend in electric vehicle drive motors.

Motorneo is gradually transitioning from using 0.35mm materials to 0.20-0.30mm products, with some batches even using 0.10mm and 0.20mm products.

axial flux motor in aircraft propulsion

Research and Development of New Motor Lamination Materials

Internationally, research and application of new core materials have become a hot topic. Various countries are accelerating research and development efforts.

In China, significant progress has been made in the research and application of new core materials. Research and development bases have been established to continually enhance the quality and performance of new core materials, contributing to the development of the country’s motor industry.

Conclusion

In summary, to ensure optimal performance and energy efficiency, electric motors rely on electrical steel laminations. These thin layers of specialized metal alloys sheet, typically electrical steel, are stacked together to form the core of the motor.

The research and application of new electric motor core laminations materials are crucial for improving motor efficiency, reducing energy losses, lowering energy consumption, and driving the development of the motor industry.

In the future, the research and application of new laminated core materials will continue to expand, further propelling the development of the motor industry and achieving its transformation, upgrade, and sustainable growth.

FAQS

What is the significance of using 6.5%Si high-silicon steel Lamination Materials for driven Electric motors?

6.5%Si high-silicon steel is ideal for low-noise, low iron loss transformers, and high-frequency motors due to its optimal magnetic properties. However, its brittleness poses challenges in manufacturing.

How does Motorneo address the demand for thinner core materials in the automotive industry?

Motorneo recognizes the trend towards thinner core materials in automotive drive motors. We provide silicon steel materials ranging from 0.1mm to 1mm, catering to the industry’s evolving requirements for reduced iron losses and increased mechanical strength.

How is the thickness of the silicon steel materials offered by you?

Our silicon steel materials, ranging from 0.1mm to 1mm, provide a versatile solution for rotor and stator cores. These materials offer benefits such as specific thickness options, allowing for customization based on motor requirements. Additionally, our expertise in providing nickel-cobalt alloys can further cater to diverse industrial needs.

Thinner gauges of non-oriented silicon steel reduce iron losses in automotive motor stators and rotor cores, aligning with the trend towards increased efficiency and mechanical strength.

What Is Non Grain-Oriented Electrical Steel?

Non grain-oriented electrical steel is a magnetic steel designed for electrical applications, featuring random grain orientation for isotropic magnetic properties. 

It is commonly coated with insulating materials, such as oxides or varnishes, to minimize core losses and improve saturation in rotating machinery in transformers, motors, and generators.

Try to contact us for high-quality motor cores in China.