| Abstract Scope |
Soft magnetic composites (SMCs), key materials for electric motors, need to be optimized for the energy transition. The conventional process of pressing and curing has several disadvantages that limit the magnetic properties of these composites. There is a significant amount of residual stress in final component because of the pressing process, which reduces magnetic permeability and increases magnetic hysteresis losses. During curing, such stresses may be reduced. But common SMC coatings, such as epoxy resin, degrade at low temperatures, limiting the cure temperature and the amount of stress relieved. In contrast, Fe/FexOy-type coatings are resistant to higher temperatures and provide excellent magnetic properties.
It was selected to manufacture Fe/FexOy one based on water as the key agent, as opposed to the phosphoric acid used to make the common phosphate coated SMCs.
This makes these types of SMCs a more environmentally friendly and sustainable alternative. Aiming to maximize the magnetic properties of Fe/FexOy this work examines the fabrication of Fe/FexOy SMCs from powders with different morphologies and sizes. There are three types of iron powder grades considered, namely small spherical, small flattened, and large irregular, oxidized in water and the resulting SMCs are characterized by SEM, XPS, and magnetometry. |