New Powdered Nanocrystalline Soft Magnetic Composites with Portland Cement Binder

Toroidal cores based on nanocrystalline powder Fe73Si16B7Cu1Nb3 (of Finemet type) and Portland cement 'M-500' as a binder are fabricated using powder metallurgy methods (where no pressing is applied).The cores exhibit reliable strength, temperature resistance up to 300C, and excellent magnetic properties.Using these composites provides lower losses and more stable frequency characteristics of the cores as compared to the cores for power electronics based on carbonyl-iron powders, AlSiFe, or high-silicon electrical steel.Additionally, such composites can be used for production of the devices operating at elevated temperatures, e.g., magnetic flux concentrators for induction heaters.Since these soft magnetic composites do not require pressing operations, the cores' manufacturing process is simplified significantly and enables diversification of core shapes and sizes. Key words: nanocrystalline alloy