The crystal grains in an iron powder core, made form an insulation coated iron powder through a compaction process, recrystallize into smaller grains during stress relief annealing after the compaction. In this study, the method to suppress the recrystallization is investigated to reduce the hysteresis loss of the iron powder core. The iron powder properties have an influence on the recrystallization behavior: an iron powder core with coarser crystal grain size is obtained by a decrease in the compaction strain acting as the recrystalline nucleus due to an increase in apparent density, average particle diameter, and crystal grain size of the iron powder. In addition, recrystallized grain growth is accelerated by reduction of impurity in the iron powder. The iron loss of the iron powder core with crystal grain size of 37 μm shows an iron loss lower than that of a typical electrical steel core with a thickness of 0.35 mm.
|ジャーナル||JFE Technical Report|
|出版ステータス||出版済み - 3 2016|
All Science Journal Classification (ASJC) codes