Fe-based amorphous alloy, powder core using the same, and coil encapsulated powder core
View Patent ↗An Fe-based amorphous alloy of the present invention has a composition formula represented by Fe 100-a-b-c-x-y-z-t Ni a Sn b Cr c P x C y B z Si t , and in the formula, 0 at %≦a≦10 at %, 0 at %≦b≦3 at %, 0 at %≦c≦6 at %, 6.8 at %≦x≦10.8 at %, 2.2 at %≦y≦9.8 at %, 0 at %≦z≦4.2 at %, and 0 at %≦t≦3.9 at % hold. Accordingly, an Fe-based amorphous alloy used for a powder core and/or a coil encapsulated powder core having a low glass transition temperature (Tg), a high conversion vitrification temperature (Tg/Tm), and excellent magnetization and corrosion resistance can be manufactured.
1. An Fe-based amorphous alloy represented by a composition formula: Fe 100-a-b-c-x-y-z Ni a Sn b Cr c P x C y B z , wherein
an addition amount a of Ni satisfies 4 at %≦a≦6 at %,
an addition amount b of Sn satisfies 0 at %≦b≦3 at %,
an addition amount c of Cr satisfies 0 at %≦c≦6 at %,
an addition amount x of P satisfies 6.8 at %≦x≦10.8 at %,
an addition amount y of C satisfies 2.2 at %≦y≦9.8 at %, and
an addition amount z of B satisfies 0 at %≦z≦4.2 at %,
and wherein the alloy has a glass transition temperature (Tg) equal to or lower than 740K.
2. The Fe-based amorphous alloy according to claim 1 , wherein only one of Ni and Sn, not both, has an non-zero addition amount.
3. The Fe-based amorphous alloy according to claim 1 , wherein the addition amount b of Sn is in a range of 0 to 2 at %.
4. The Fe-based amorphous alloy according to claim 1 , wherein the addition amount c of Cr is in a range of 0 to 2 at %.
5. The Fe-based amorphous alloy according to claim 4 , wherein the addition amount c of Cr is in a range of 1 to 2 at %.
6. The Fe-based amorphous alloy according to claim 1 , wherein the addition amount x of P is in a range of 8.8 to 10.8 at %.
7. The Fe-based amorphous alloy according to claim 1 , wherein the addition amount y of C is in a range of 5.8 to 8.8 at %.
8. The Fe-based amorphous alloy according to claim 1 , wherein the addition amount z of B is in a range of 0 to 2 at %.
9. The Fe-based amorphous alloy according to claim 8 , wherein the addition amount z of B is in a range of 1 to 2 at %.
10. A powder core comprising:
a powder of the Fe-based amorphous alloy according to claim 1 ; and
a binding agent solidifying the powder.
11. A coil-encapsulating powder core comprising:
a powder core formed of a powder of the Fe-based amorphous alloy according to claim 1 and a binding agent solidifying the powder; and
a coil encapsulated in the powder core.
12. The Fe-based amorphous alloy according to claim 1 , wherein a=6, b=0, c=1, x=10.8, y=7.8, and z=2.
13. The Fe-based amorphous alloy according to claim 1 , wherein a=6, b=0, c=2, x=10.8, y=7.8, and z=2.
14. An Fe-based amorphous alloy represented by a composition formula: Fe 100-a-b-c-x-y-z Ni a Sn b Cr c P x C y B z , wherein
an addition amount a of Ni satisfies 4 at %≦a≦6 at %,
an addition amount b of Sn satisfies 0 at %≦b≦3 at %,
an addition amount c of Cr satisfies 1 at %≦c≦6 at %,
an addition amount x of P satisfies 6.8 at %≦x≦10.8 at %,
an addition amount y of C satisfies 2.2 at %≦y≦9.8 at %, and
an addition amount z of B satisfies 0 at %≦z≦4.2 at %,
wherein the alloy has a glass transition temperature (Tg) equal to or lower than 740K, and a conversion vitrification temperature (Tg/Tm) equal to or greater than 0.52, Tm being a temperature of a melting point of the alloy.
15. An Fe-based amorphous alloy represented by a composition formula: Fe 100-a-b-c-x-y-z Ni a Cr c P x C y B z , wherein
an addition amount a of Ni is 6 at %,
an addition amount c of Cr is 2 at %,
an addition amount x of P is 10.8 at %,
an addition amount y of C is 7.8 at %, and
an addition amount z of B is 2 at %,
wherein the alloy has a glass transition temperature (Tg) equal to or lower than 710K, and a conversion vitrification temperature (Tg/Tm) equal to or greater than 0.557, Tm being a temperature of a melting point of the alloy.
16. A powder core comprising:
a powder of the Fe-based amorphous alloy according to claim 15 ; and
a binding agent solidifying the powder,
wherein a core loss (W) at 25 mT and 100 kHz is equal to or smaller than 60 kW/m 3 .
17. A coil-encapsulating powder core comprising:
a powder core formed of a powder of the Fe-based amorphous alloy according to claim 15 and a binding agent solidifying the powder; and
a coil encapsulated in the powder core,
wherein a core loss (W) at 25 mT and 100 kHz is equal to or smaller than 60 kW/m 3 .