Electrical Applications II

SOFT MAGNETICS


To guide or enhance magnetic flux in devices, you can use soft magnetic materials. These materials show narrow hysteresis loops with coercivities Hc < 1000 A/m and thus can easily be magnetized with comparable low magnetic field intensities H (see figure 1). This enables fast switching speeds between possible states of magnetic flux densities B with only little hysteresis losses.

 

SOFT MAGNETIC COMPOSITES (SMC)


Soft magnetic composites are made of iron powder, with every grain enveloped by an electrical insulation layer (see figure 2). Within the SMC bulk material, the ferromagnetic iron cores allow a homogeneous and isotropic magnetic behavior in three dimensions. Magnetizing curves of different SMC are shown in figure 3. Like that, SMC represent a promising alternative to conventional used laminated steel cores for electromagnetic applications, providing several advantages. The insulation shell prevents a system suffering from high eddy current losses. The behavior of core losses of SMC in comparison to laminated steel is given in figure 4. Especially for medium and high frequencies, SMC is favorable. Flexibility in design for electrical machines is gained and production costs will be minimized by using SMC.


figure 2

 

 

SOFT MAGNETIC AND SMC MATERIAL


Each application requires specific properties. We help to define the right combination of material and application. Besides conventional SMC materials from suppliers, PMG offers its own brand SIRON®S. For prototyping, we developed the unique SIRON®S-b materials, capable for machining processes. Relevant properties are listed in table 1.


Table 1: Collection of mechanical and magnetic properties of offered SIRON®S materials. On the very left side considered properties are listed, on the right the different materials. Materials are collated in machinable (suffix b) and non-machinable.

 

You are interested in further information and a detailed overview about soft magnetic materials, SMC and SIRON®? Please feel free to contact our experts.