Abstract
A fundamental study was made mainly on the (DC) magnetic properties of Fe-Si type magnetic alloys, prepared by the two methods of soft-iron/Fe-21(wt%)Si mixed powders and full alloy powders. In this case, Fe-21Si (eutectic) mother alloy fine was made by high-pressure water atomization and was blended with soft-iron powder to Fe-0-8(wt%)Si compositions.
The results obtained were summarized as follows:
(1) Magnetic induction (B10) have the maximum value in the Si content: 2-3wt%, under the influence of γ-loop on Fe-rich side and Si substitution by Fe in higher Si region, almost for all the sintering temperatures (≥1473K).
(2) Max. permeability (μm) shows the two maximum values in the Si contents: 3 and 7wt%, as partly confirmed of C/W Fe-Si alloy, under the influence of crystal anisotropy and magnetostriction.
(3) Coercive force (Hc) tends to simply decrease with the rise of Si content, except for higher Si region (sintered at 1373K) and to be structure-sensitive as well as max. permeability (μm), depending on pore morphologies.
(4) On a whole, magnetic properties (B10, μm, Hc) of Fe-3, 6.5, 8(wt%)Si-mixed powders are on improved level compared with those of full alloy powders, probably due to good compressibility and sinterability.
(5) Electric resistivity (ρ) increases linearly with the rise of Si content and radially crushing strength (σ) tends to have the maximum value in the Si content: 5wt%, together with higher strain (ε), for all the sintering temperatures (≥1473K).
