Soft magnetic powder and magnetic shield composition
AssigneeTDK Corporation
InventorsMasao Shigeta, Asako Kajita, Ippo Hirai
Life of this patent
Estimating the term…
Abstract
Soft magnetic powder comprising flat soft magnetic particles of an alloy having a composition defined and encompassed by polygon ABCDE in a Fe-Si-Cr ternary composition diagram of FIG. 1 or polygon JKLMN in a Fe-Si-Al ternary composition diagram of FIG. 4 is suitable for use in magnetic shields. The flat soft magnetic particles are prepared by furnishing alloy particles having a predetermined composition, flattening them, and heat treating the flat particles to develop a peak corresponding to plane index (002) in an X-ray diffraction diagram thereof.
Claims12
A soft magnetic powder for use in magnetic shield comprising flat soft magnetic particles of an alloy having a composition defined and encompassed by polygon ABCDE in a ternary composition diagram of Fe, Si, and Cr wherein points A, B, C, D, and E have the following compositions as expressed in atomic percentage
- A:
- Fe.sub.78 Si.sub.22 Cr.sub.0
- B:
- Fe.sub.70 Si.sub.30 Cr.sub.0
- C:
- Fe.sub.60 Si.sub.30 Cr.sub.10
- D:
- Fe.sub.63 Si.sub.18 Cr.sub.19
- E:
- Fe.sub.76 Si.sub.18 Cr.sub.6
- wherein said flat soft magnetic particles have a weight average particle diameter D.sub.50 of 5 to 30 .mu.m and an average thickness of up to 1 .mu.m, the average particle diameter divided by the average thickness being from 10 to 3,000.
A soft magnetic powder for use in magnetic shields comprising flat soft magnetic particles of an ally having a composition defined and encompassed by polygon JKLMN in a ternary composition diagram of Fe, Si, and Al wherein points J, K, L, M, and N have the following compositions as expressed in atomic percentage:
- J:
- Fe.sub.83.8 Si.sub.9.2 Al.sub.7
- K:
- Fe.sub.84.7 Si.sub.9.3 Al.sub.6
- L:
- Fe.sub.85.6 Si.sub.10.4 Al.sub.4.0
- M:
- Fe.sub.84.9 Si.sub.11.1 Al.sub.4.0
- N:
- Fe.sub.83.2 Si.sub.9.8 Al.sub.7
- wherein the flat soft magnetic particles show a peak corresponding to plane index (002) in an X-ray diffraction diagram thereof and wherein said flat soft magnetic particles have a weight average particle diameter D.sub.50 of 5 to 30 .mu.m and an average thickness of up to 1 .mu.m.
A soft magnetic powder for use in magnetic shields comprising flat soft magnetic particles of an alloy having a composition defined and encompassed by polygon FGHIE in a ternary composition diagram of Fe, Si, and Cr wherein points F, G, H, I, and E have the following composition as expressed in atomic percentage
- F:
- Fe.sub.77 Si.sub.20 Cr.sub.3
- G:
- Fe.sub.71 Si.sub.26 Cr.sub.3
- H:
- Fe.sub.62 Si.sub.26 Cr.sub.12
- I:
- Fe.sub.70 Si.sub.18 Cr.sub.12
- E:
- Fe.sub.76 Si.sub.18 Cr.sub.6
- wherein said flat soft magnetic particles have a weight average particle diameter D.sub.50 of 5 to 30 .mu.m and an average thickness of up to 1 .mu.m, the average particle diameter divided by the average thickness being from 10 to 3,000.
A soft magnetic powder for use in magnetic shields comprising flat soft magnetic particles of an alloy having a composition defined and encompassed by polygon JKLQR in a ternary composition diagram of Fe, Si, and Al wherein points j, K, L, Q, and R have the following compositions as expressed in atomic percentage:
- J:
- Fe.sub.83.8 Si.sub.9.2 Al.sub.7
- K:
- Fe.sub.84.7 Si.sub.9.3 Al.sub.6
- L:
- Fe.sub.85.6 Si.sub.10.4 Al.sub.4.0
- Q:
- Fe.sub.85.1 Si.sub.10.9 Al.sub.4.0
- R:
- Fe.sub.83.5 Si.sub.9.5 Al.sub.7.0
- wherein the flat soft magnetic particles show a peak corresponding to plane index (002) in an X-ray diffraction diagram thereof and wherein said flat soft magnetic particles have a weight average particle diameter D.sub.50 of 5 to 30 .mu.m and an average thickness of up to 1 .mu.m.
Dependencies are inferred from the claim text.