Measurement & Testing Systems
MagHyst® for Soft Magnetic Materials

The selection of an appropriate soft magnetic material is a critical step in the development and simulation of electromagnetic systems such as solenoid valves, fuel injectors, brakes, and relays.

The material significantly influences the performance of the magnetic circuit and, consequently, the overall behavior of the system.

Magnetically conductive components, including magnetic cores, armatures, yokes, coil formers, and other structural elements, are manufactured from a wide range of materials depending on the design requirements.

These range from conventional steels and cast irons to highly specialized soft magnetic materials with precisely defined magnetic properties.

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The Importance of Material Characteristics in FEM Simulation

For finite element analysis (FEA) of electromagnetic systems, the magnetic B-H characteristic curve is one of the most important input parameters. Its significance is comparable to that of the system's geometric design.

While geometry and construction can generally be regarded as well-defined constants with tight tolerances, magnetic material properties often exhibit substantially greater variation. These variations may occur between production batches, between different material suppliers, or even within a single delivery lot.

For many unalloyed or standardized steels, magnetic properties are not guaranteed and can vary by several tens of percent. In practice, these variations are often a major reason for discrepancies between simulation results and the actual behavior of the physical component.

The more highly optimized an electromagnetic system becomes and the tighter the allowable tolerances are defined, the more critical it is to have accurate knowledge of the material's actual magnetic properties.

MagHyst® for Determining B-H Characteristic Curves

MagHyst® measurement systems enable the precise determination of magnetic B-H characteristic curves for soft magnetic materials and components.
For this purpose, standardized test specimens are manufactured from the raw material. Depending on the material type, different specimen configurations can be used, including:

  • Solid materials (e.g., bar stock)
  • Sheet metal or strip material
  • Powder-based or composite materials (depending on the application)

Specimen Geometries and Measurement Setup

The following specimen geometries have proven particularly suitable for magnetic characterization:

  • Ring specimens (toroidal cores)
  • Rod specimens
  • Strip specimens

Solid materials are typically machined into ring or rod specimens. Sheet and strip materials are either cut into strip specimens or stacked into toroidal cores to achieve a defined cross-sectional geometry and magnetic flux path.

Measurement Principle

For ring specimens, two uniformly distributed windings are applied:

  • Excitation winding for magnetizing the specimen
  • Measurement winding for detecting changes in magnetic flux

For rod and strip specimens, dedicated measurement fixtures are used, including:

  • Rod adapters
  • Strip adapters

These fixtures enable reproducible and standards-compliant magnetic characterization even for non-toroidal specimen geometries.

Measurement Results and Material Parameters

The measurement provides the complete magnetic hysteresis loop, from which all relevant material parameters can be derived, including:

  • Coercive field strength (Hc)
  • Remanent flux density (Br)
  • Maximum permeability (μmax)
  • Saturation behavior
  • Hysteresis losses

The complete hysteresis loop can be measured within seconds, making it suitable for both rapid quality assessment and detailed material characterization.

Determination of the Initial Magnetization Curve

For finite element analysis (FEA), the initial magnetization curve is of particular importance.

To determine this characteristic, the specimen is first demagnetized under controlled conditions. The complete hysteresis loop, including the initial magnetization curve, is then recorded.

This dataset provides a realistic representation of material behavior for use in numerical simulation models.

Integration into FEA Workflows

The measured characteristic curves can be exported directly and imported into common FEA simulation environments. This creates a consistent link between actual material behavior and virtual product design.

As a result, discrepancies between simulation results and production hardware can be significantly reduced, improving the predictive accuracy of electromagnetic system simulations from the earliest stages of development.

Importance for Industrial Applications

As requirements for efficiency, miniaturization, and functional integration in electromagnetic systems continue to increase, precise knowledge of magnetic material properties becomes increasingly important.

MagHyst® not only enables the measurement of standardized magnetic material parameters but also provides direct insight into real manufacturing variations. This creates a reliable foundation for:

  • Robust FEA-based design
  • Shorter development cycles
  • Reduced component variation
  • Improved production consistency
  • Reproducible product quality

As a result, magnetic material characterization becomes an integral part of modern electromagnetic product development.