The influence of production methods on the magnetic performance of electrical steels and soft magnetic composites

Magnetic measurements of electrical steels and soft magnetic composites (SMC) have been conducted on samples with the same toroidal geometry. Steel lamination samples have been manufactured using various methods to investigate the effect of cutting procedures on losses over a range of frequencies, flux densities, and temperatures. The measurements show that the SMC requires a higher field strength to achieve the same polarization and has a lower maximum permeability than the lamination samples. SMCs present less iron loss at elevated frequencies due to their lower electrical conductivity, but the opposite is true at lower frequencies due to higher hysteresis. At a certain cross-over frequency, the specific core loss of SMC is lower than electrical steels, this point can vary dramatically depending on the production method. The characteristic behavior arises from SMCs insulated particle microstructure. Considering typical high-speed machine working requirements, SMC is shown to operate more efficiently at all values of magnetic flux densities considered.