Transformer core refers to a sintered magnetic metal oxide composed of various iron oxide mixtures. For example, manganese-zinc ferrite and nickel-zinc ferrite are typical magnetic core materials. Silicon steel and FeSiAl materials have high saturation magnetic induction values Bs, but their effective magnetic permeability values are low, especially in the high frequency range;
Permalloy has high initial permeability, low coercivity and loss, and stable magnetic properties, but Bs is not high enough. When the frequency is greater than 20kHz, the loss and effective permeability are not ideal, the price is more expensive, and the processing and heat treatment are complicated.
Co-based amorphous alloy has high permeability, low Hc, low loss in a wide frequency range, close to zero saturation magnetostriction coefficient, insensitive to stress, but low Bs value and expensive.