The desire for newer and better technology has extended to electric motor applications. The emergence of powder metal parts made of soft magnetic composite is posing a challenge to traditional lamination (electrical) steel motor construction.
Consider laminated steel parts to be the safe, old-school method of producing electric-based parts. Meanwhile, soft magnetic composites (SMCs) are uncharted territory for motor and other similar applications.
The following characteristics distinguish soft magnetic composite from laminated steel. By the end of this article, you should have a good idea of where you want to take your next project.
Magnetism
The manufacturing process is arguably the most important factor in how magnetic properties of a component turn out.
For laminations, complex processes include:
Punching
Stacking
Welding
Thrilling
Pressing
The interior of the material is deformed as a result of this series of processes, resulting in weaker magnetic properties.
Because ferromagnetic materials (such as SMCs) have a different structure, the distribution of magnetic losses in them will be different.
SMCs have higher hysteresis losses (energy wasted as heat). However, eddy current losses are significantly lower in soft magnetic composites. Because SMCs are more difficult to magnetize, they have a higher hysteresis loss. Because the tiny composite particles are so isolated, their eddy losses are reduced.
The total loss characteristics of any magnetic material can be calculated by combining these two statistics. But what we really need to know is that the superior magnetic properties of SMCs can enable new ideas that would otherwise be impossible to realize with traditional laminations.
2D magnetic flux path VS 3D magnetic flux path
To avoid magnetism loss in the direction perpendicular to the laminate, lamination steel motor construction is limited to 2D magnetic flux. The radial flux motor is a prime example of this.
Because soft magnetic composites generate a 3D magnetic flux path, the possibilities are limitless. 3D printing allows for more innovative and high-performance motor designs and ideas.
Because of the composition of SMC material and its net shaping capability, you can introduce new 3D solutions with minimal iron (magnetic) loss and optimized copper winding. Only SMC can improve the performance and capabilities of a standard motor through unique design elements.
Density of Power
Electric machines' power density can be increased by using soft magnetic composites. They can even outperform the power density of a machine made of lamination steels when used intelligently and intuitively.
Because laminations are fully dense steel, there will be differences in raw material density when compared to SMCs. However, keep in mind that with laminates, metal is stacked and pressed into frames.
It's the equivalent of being forced to use a cookie cutter rather than being free to arrange the batter however you want.
As previously stated, powder metallurgy is the only process capable of producing net shape components for the automotive industry (gear box parts, motor parts, etc.).
Soft magnetic composites may be useful in the following electric motor applications:
High-efficiency motors perform best in electrical machines with 3D magnetic flux. Furthermore, there are new applications that require high operating frequencies. Because they provide ideal magnetic properties at higher frequencies, soft magnetic powder composites are the answer.
As a result, powder metal components are ideal for applications with limited space. Automobiles are among these applications, but others include:
