Tailoring the Microstructure of Soft Magnetic Composites for Electric Motor Applications
- Resource Type
- Periodical
- Authors
- Schuller, D.; Hohs, D.; Schweizer, S.; Goll, D.; Schneider, G.
- Source
- IEEE Transactions on Magnetics IEEE Trans. Magn. Magnetics, IEEE Transactions on. 55(2):1-4 Feb, 2019
- Subject
- Fields, Waves and Electromagnetics
Powders
Annealing
Magnetic hysteresis
Soft magnetic materials
Strain
Grain size
Microstructure
Electric motor
electron backscatter diffraction (EBSD)
microstructure
soft magnetic composite (SMC)
- Language
- ISSN
- 0018-9464
1941-0069
Soft magnetic composite (SMC) material has been fabricated using 9 different powder particle fractions (smallest fraction: $< 50~\mu \text{m}$ and largest: $> 400~\mu \text{m}$ ). The microstructure features and resulting magnetic properties have been quantified and correlated. A specific focus lies on simultaneous consideration of the effects of particle size and internal grain size. Analysis has been carried out on samples in green condition and samples annealed between 400 °C and 600 °C. Electron backscatter diffraction technology brings about a substantially additional value to characterize deformations inside the grains. By detailed advanced microstructure analysis, it is shown that the deformation and recrystallization behavior is significantly different for different particle sizes used. Particle sizes between 100 and $200~\mu \text{m}$ show grain size distributions with the largest grains ( $\text{d}_{50} \sim 44~\mu \text{m}$ ) in the volume of the particles resulting in the lowest hysteresis losses ( $P_{\text {H}} \sim 4$ W/kg, 1 T, 50 Hz). The relationship between particle and internal grain size distribution has been analyzed to enable further improvement of SMC materials concerning hysteresis loss reduction.