NTN Corporation has developed a high-performance magnetic core with the highest level of magnetic properties and strength by coating the surface of iron power with thermosetting resin and applying compression moulding.
The newly developed high-performance magnetic core uses iron powder for powdered metallurgy as the magnetic powder, with a proprietary mix of thermosetting resin added for granulation processing to apply an insulating coating over the surface of the iron. A special type of compression moulding and thermal hardening help to limit damage to the coating.
These features reduce contact between powders, and the saturated magnetic flux density – the market index for magnetic properties – is improved by 10%, the relative permeability is increased by 30%, and the iron loss is reduced by 15% to achieve the industry’s highest level of magnetic properties. The radial crushing strength is also five times that of commercially available products, which drastically improves core cutting work and handling. Utilisation of the developed product brings improvements to induction hardening efficiency for more accurate hardening, which helps to reduce the time required for heat treatment, and increase both strength and hardness of machined parts.
The high-performance magnetic core is already in use with equipment at NTN; however, the product is being marketed to new manufacturers of induction hardening equipment and high-frequency heat treatment machining companies.