The effect of compact densification on the soft magnetic properties of Fe-based amorphous P/M cores mixed with pure iron powder

S.C. Yoon, K.S. Kim, K.Y. Sohn, M.R. Kim, Y.S. Song, W.W. Park
Inje University, KR

Keywords: SMC, densification, amorphous, pure iron powder, compaction

Summary:

The void in the compact leads to lower green density and causes poor magnetic properties, especially in permeability and coercivity. Therefore, this paper has the aim to improve the compactability and density of the amorphous powder compacts. The effects of densification on the magnetic properties have been studied in the Fe-based amorphous powder core mixed with pure iron powder. And, to evaluate the effect of powder size on magnetic properties, the rapidly solidified amorphous powders were sieved and separated from different groups of particle size, classified as 150 ~ 200 mesh, 200 ~ 270 mesh and below 270 mesh. The three group of amorphous powders were mixed with 10.wt% pure iron powder with spherical shape, respectively. The powder mixtures were mixed with 1.5 wt.% silicone polymer binder, and then heat treated at 250 °C for 1 h for curing of polymer. For the consolidation, the powder mixtures were compacted into a cylindrical die with lubricant to form toroid-shaped cores. As a result, the density of the powder mixtures were pronouncely increased, of which magnetic flux density and permeability was much higher than that of conventional amorphous powder core. The core loss decreased with decreasing the amorphous powder sizes.