Effect of Annealing Temperature on the Soft Magnetic Behavior of Sendust Powder Core

Abstract

The variation of soft magnetic properties of Sendust powder cores as a function of annealing temperature has been investigated. Toroid-shaped Sendust powder cores were prepared from Fe-Si-Al powder by machine pulverizing and subsequent cold pressing using inorganic insulating layer and organic binders, respectively. The influence of different compaction pressures and various annealing temperature on effective permeability and quality factor was investigated. Sendust powder cores using inorganic salt as insulating layer exhibit high effective permeability ( μe>110) up to 1 MHz, showing excellent frequency stable characteristics and high quality factor (Q>80) at 50 kHz. The optimized annealing temperature is 953K.