Soft Magnetic Materials & the Electrification of Transportation


Experts have been saying for years that many industries will soon need new and better materials for their electromagnetic applications. That future is now. 

Innovation-minded engineers are looking to a new solution for electric motor designs and similar applications. Powder metallurgy may be your best soft magnetic material solution for both AC and DC applications.

The best way to use these materials is powder metal, where you can shape them freely. In powder metallurgy, these materials fall under two umbrellas: soft magnetic composite materials (SMCs) and sintered soft magnetic materials. This resource center will help you understand which is better for your project, as your solution may differ by application, industry, or property needs.

Click below and we’ll take you to the appropriate starting point:

Uses of Sintered Soft Magnetic Materials (DC applications):

  • Solenoids
  • Magnet stators for brushed DC motors
  • Rotors for synchronous motor design using a permanent magnet
  • Almost any other motor, including brushless DC electric motor design

Uses of Soft Magnetic Composites (AC applications):

  • Stators
  • Low-speed rotors -- the stresses aren’t as high as you think!
  • AC permanent magnet motor design
  • Any application where you want to optimize your part’s shape
  • Any application where you want to conserve copper wire

SMC Performance Trait Audit

What’s the Difference Between SMCs & Sintered Soft Magnetic Materials?

Soft magnetic composites and sintered soft magnetic materials have two distinct ranges of applications.

  • Soft magnetic composites are for AC applications
  • Sintered soft magnetics are for DC applications

To understand why, look at the way manufacturers treat these materials. Sintered soft magnetics, as the name implies, undergo a higher-temperature treatment (sintering) for particle-to-particle bonding to improve strength and ductility (among other properties). They also give you the option of alloying materials. SMCs receive a lower-temperature treatment to preserve the individual particle identity. This process change minimizes heat inefficiency and maximizes magnetic performance.

What does that look like in practice? If you specified an SMC for a steering wheel component, the response would be too slow and the driver would end up crashing into a tree. Similarly, if you put sintered soft magnetics in an AC electric motor design, the motor essentially becomes a giant heater that’s wildly inefficient.

We implore you to learn more about each material. When used correctly in the right application, they’re superior to every competing process on the market.


If you’re already experimenting with new electric motor solutions that are a little different, consider incorporating powder metallurgy into your plan:

View the Engineering Hub >


More on Soft Magnetic Composites

Heat Efficiency & Performance

In SMCs, each particle is a discreet magnetic element. We achieve this by adding a magnetic resistive coating to each particle. You can minimize heat buildup/eddy current losses, particularly at higher frequencies above 200 Hz, while adding the flexibility of 3D design. Compared with steel laminations, soft magnetic composites can offer superior efficiency -- both in magnetic performance and material use.

Soft magnetic composites are often the best material for AC custom electric motor design when you need a higher level of performance.

SMCs offer AC electromagnetic design possibilities that didn’t exist previously:

  • Lower total/eddy current losses at a wide range of frequencies
  • Incredible 3D shaping ability through advanced compaction technology
  • Lower energy consumption

For example, a low-speed rotor is highly compatible with SMCs -- the stresses are lower than you think. In a ceiling fan motor, you can combine SMCs and traditional lamination steel to achieve multiple properties and reduce the assembly size.

(Open graphic below in new tab to see full-scale version.)

Horizon SMC Design Considerations Infographic - Combined PNG Version

More on Sintered Soft Magnetic Materials

Speed & Performance

Since alloying is only feasible in sintered parts, that’s the route you’ll take if you need the properties of phosphorus or silicon in your component.

Sintered soft materials are ideal:

  • When you need rapid response, such as in solenoids for gas/liquid modulation
  • In rotors for synchronous motor design using a permanent magnet, so you can incorporate intricate shape-making and holes
  • If you want to use magnets on a unique stator shape without wasting material

Engineers commonly compare stamping vs. powder metallurgy. We’ll make it easier for you by showing the numbers for stamped steel laminations vs. sintered powder magnetics. You’ll see that in powder metallurgy, the properties of soft magnetic materials give up very little in terms of performance:

properties of powder metallurgy electric motor materials - chart - property comparison-jpg-1-1

Meet Our Experts on Soft Magnetic Material Applications

Fran has the knowledge and experience in materials and processing to satisfy your component requirements. If you have questions on magnetic materials or powder metallurgy in general, ask the experts here!


Fran Hanejko, our Senior Advanced Materials Engineer, is an industry-leading expert with numerous published research papers under his belt. 

Resources for Soft Magnetic Materials & Motor Design

Are you completely in the dark on soft magnetic powder? All brushed up on the basics of electric motor materials but need a little more research? Or somewhere in between?

Keep reading to learn what makes powder metal materials so important to electromagnetic components in motors and more:

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For our one of our latest PM Component Spotlights, we revisited the time an iconic auto brand developed an engine mounting system keyed by a Horizon assembly.

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Comparison of Radial & Axial Flux Structures in Electrical Machines

This paper explores the advantages and disadvantages of single-sided and inside rotor axial flux geometries when considering permanent magnet synchronous machines.

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Soft Magnetic Composites: Recent Advancements in the Technology

Our world is focused on making electrical devices faster, lighter, and overall better. Why should motors be any different? Soft magnetic material allows for revolutionized designs of electromagnetic devices. That translates to improved efficiency and reduced weight and costs -- without sacrificing magnetic performance.

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Hysteresis & Core Loss in Induction Motors: SMC Vs. Steel Lamination

Have you ever wished you had superpowers that could stop both hysteresis and eddy current loss in a project that demanded high magnetic performance? An inefficient magnetic part can bring down your whole design. A little lesson about materials can show you how to minimize hysteresis and core loss in induction motors and other AC applications.

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Motors & More: Electrical Steel Uses & Whether Powder Metal's Better

Powder metallurgy is breaking into more and more electrical applications, but how does it stack up (literally) against those old-school electrical steel laminations? Turns out some electrical steel uses and applications should stay as such, while sometimes powder metal is a great alternative. Let’s look at why engineers are still working with electrical steel and whether you’re missing out on opportunities in some cases.

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Vertical Electrical Motor Using Soft Magnetic Composites

SMCs are today a viable alternative to steel laminations in a range of new applications, such as rotating machines, fast-switching solenoids, and sensors. And you can do it while creating a fraction of the components per product! This paper focuses on how material properties are affecting the performance of a novel motor design.

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1 Big Thing Separates Soft Magnetic Materials Vs. Non-Powder Metal

Which is easier to worry about -- 1,300 components or 10 components? For decades, manufacturers have accepted as law the obstacles associated with standard lamination steels. But the emergence of soft magnetic materials for use in auto and motor parts should not be ignored by those seeking a truly unique, remarkable part. How do SMCs compete with lamination steels? Let’s take a look.

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What is Soft Magnetic Composite?

This basic article introduces SMCs to the unfamiliar engineer or purchaser. Among the points covered are how soft magnetics open new opportunities, why they matter in design, and how heat affects magnetic performance.

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1P? 3P? 5P? What Can These Powder Metal Processes Do For Your Numbers?

Powder metal does more than you might think -- if you’ve got the right material. Knowing the strengths and subtleties of each material process can make your product stand out in a competitive market. Three emerging material processes you should know about ASAP are the 1P, 3P, and 5P soft magnetic composites. Here’s how each material will bestow certain qualities on your application.

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New SMCs for Electromagnetic Applications With Improved Mechanical Properties

The chance to move from 2-D to 3-D design of electrical machines is possible thanks to soft Magnetic composites. These iron-based powders are insulated and pressed to realize shapes otherwise impossible with traditional lamination sheets. This paper presents recent progress in mixing SMC iron powders and phenolic resin, in different weight percentages and mold pressures. The goal? Compromising between magnetic and mechanical qualities.

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Induction Vs. Permanent Magnet Motor Efficiency | Auto Electrification

With the electrification of the automobile continuing at an accelerated pace, many wonder what type of motor is best for the modern electric drivetrain. There’s a strong argument to the permanent magnet motor being superior to the three-phase induction motor. The inherent advantages of powder metallurgy -- potential for increased motor performance and lower overall cost -- can be an effective tool in producing these drive systems.

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This New Generation of Direct-Drive Electric Machines Will Power Our Future

Manufacturers of wind turbines and electric machines always had to find a balance between using generators with low-weight, low-reliability systems and using heavy, high-efficiency systems. A new generation of motors and generators based on axial flux technology combines the best of both worlds. This blog post describes the difference between axial and radial flux technologies.

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COMPONENT SPOTLIGHT: Electrical Lamination + SMC Powder Metal

In many cases, soft magnetic composites aren't a cost-effective or good 1:1 replacement material for steel electrical laminations. But, what if you could marry SMCs with laminations to get an answer where 1 + 1 = 3? Here we unveil something that’s more of an opportunity than a case study of a finished application. But that doesn’t make it any less exciting!

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Advanced Soft Magnetic Materials for Power Applications

This article begins by introducing the importance of electrical steels in their application as electrical machine cores. At the center of the discussion? The origin, controlling factors, and methods of optimizing core loss -- SMCs’ most important magnetic parameter. Powder composite materials are now making their way into niche power device applications, so the article compares their magnetic properties with lamination steels’.

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