Nano-crystalline, magnetic alloy, its production method, alloy ribbon and magnetic part
View Patent ↗A magnetic alloy having a composition represented by the general formula of Fe 100-x-y Cu x B y (atomic %), wherein x and y are numbers meeting the conditions of 0.1≦x≦3, and 10≦y≦20, or the general formula of Fe 100-x-y-z Cu x B y X z (atomic %), wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 0.1≦x≦3, 10≦y≦20, 0<z≦10, and 10<y+z≦24), the magnetic alloy having a structure containing crystal grains having an average diameter of 60 nm or less in an amorphous matrix, and a saturation magnetic flux density of 1.7 T or more.
1. A method for producing a magnetic alloy, comprising the steps of quenching an alloy melt comprising Fe and a metalloid element to produce a Fe-based, fine crystalline alloy having a structure in which crystal grains having an average diameter of 30 nm or less are dispersed in an amorphous matrix in a proportion of more than 0% by volume and 30% by volume or less, and heat-treating said Fe-based, fine crystalline alloy to have a structure in which body-centered-cubic crystal grains having an average diameter of 60 nm or less are dispersed in an amorphous matrix in a proportion of 30% or more by volume,
wherein said magnetic alloy has a saturation magnetic flux density of 1.7 T or more, a coercivity of 24 A/m or less, and a composition represented by the following general formula (1):
Fe 100-x-y Cu x B y (atomic %) (1),
wherein x and y are numbers meeting the conditions of 0.1≦x≦3, and 10≦y≦20.
2. The method for producing a magnetic alloy according to claim 1 , wherein the crystal grains in said Fe-based, fine crystalline alloy have an average diameter of 20 nm or less.
3. The method for producing a magnetic alloy according to claim 2 , wherein the crystal grains in said Fe-based, fine-crystalline alloy have an average diameter of 0.5 to 20 nm.
4. The method for producing a magnetic alloy according to claim 1 , wherein said alloy melt is quenched with a roll, and wherein the volume fraction of the crystal grains in said Fe-based, fine crystalline alloy is changed with the rotation speed of said roll.
5. The method for producing a magnetic alloy according to claim 1 , wherein an average distance between the crystal grains in said Fe-based, fine-crystalline alloy is 50 nm or less.
6. The method for producing a magnetic alloy according to claim 1 , wherein said Fe-based, fine-crystalline alloy is subjected to a heat treatment comprising heating to a highest temperature of 430° C. or higher at a maximum temperature-elevating speed of 100° C./minute or more, and keeping at the highest temperature for 1 hour or less.
7. The method for producing a magnetic alloy according to claim 6 , wherein a temperature-elevating speed at 300° C. or higher is 150° C./minute or more.
8. The method for producing a magnetic alloy according to claim 1 , wherein said Fe-based, fine-crystalline alloy is subjected to a heat treatment comprising keeping at a highest temperature of 350° C. or higher and lower than 430° C. for 1 hour or more.
9. The method for producing a magnetic alloy according to claim 8 , wherein the time of keeping at the highest temperature is 1 to 24 hours.
10. The method for producing a magnetic alloy according to claim 8 , wherein an average temperature-elevating speed in said heat treatment is 0.1-200° C./minute.
11. The method for producing a magnetic alloy according to claim 1 , wherein a part of Fe is substituted by Ni and/or Co in a proportion of 10 atomic % or less based on Fe.
12. The method for producing a magnetic alloy according to claim 1 , wherein a part of Fe is substituted by at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, platinum-group elements, Au, Ag, Zn, In, Sn, As, Sb, Bi, Y, N, O and rare earth elements in a proportion of 5 atomic % or less based on Fe.
13. A method for producing a magnetic alloy, comprising the steps of quenching an alloy melt comprising Fe and a metalloid element to produce a Fe-based, fine crystalline alloy having a structure in which crystal grains having an average diameter of 30 nm or less are dispersed in an amorphous matrix in a proportion of more than 0% by volume and 30% by volume or less, and heat-treating said Fe-based, fine crystalline alloy to have a structure in which body-centered-cubic crystal grains having an average diameter of 60 nm or less are dispersed in an amorphous matrix in a proportion of 30% or more by volume,
wherein said magnetic alloy has a saturation magnetic flux density of 1.7 T or more, a coercivity of 24 A/m or less, and a composition represented by the following general formula (2):
Fe 100-x-y-z Cu x B y X z (atomic %) (2),
wherein X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers meeting the conditions of 1.2≦x1.6, 10≦y≦20, 0≦z≦10, and 10<y+z≦24.
14. The method for producing a magnetic alloy according to claim 13 , wherein said X is Si and/or P.
15. The method for producing a magnetic alloy according to claim 13 , wherein the crystal grains in said Fe-based, fine crystalline alloy have an average diameter of 20 nm or less.
16. The method for producing a magnetic alloy according to claim 15 , wherein the crystal grains in said Fe-based, fine-crystalline alloy have an average diameter of 0.5 to 20 nm.
17. The method for producing a magnetic alloy according to claim 13 , wherein said alloy melt is quenched with a roll, and wherein the volume fraction of crystal grains in said Fe-based, fine crystalline alloy is changed with the rotation speed of said roll.
18. The method for producing a magnetic alloy according to claim 13 , wherein an average distance between the crystal grains in said Fe-based, fine-crystalline alloy is 50 nm or less.
19. The method for producing a magnetic alloy according to claim 13 , wherein said Fe-based, fine-crystalline alloy is subjected to a heat treatment comprising heating to a highest temperature of 430° C. or higher at a maximum temperature-elevating speed to 100° C./minute or more, and keeping at the highest temperature for 1 hour or less.
20. The method for producing a magnetic alloy according to claim 19 , wherein a temperature-elevating speed at 300° C. or higher is 150° C./minute or more.
21. The method for producing a magnetic alloy according to claim 13 , wherein said Fe-based, fine-crystalline alloy is subjected to a heat treatment comprising keeping at a highest temperature of 350° C. or higher and lower than 430° C. for 1 hour or more.
22. The method for producing a magnetic alloy according to claim 21 , wherein the time of keeping at the highest temperature is 1 to 24 hours.
23. The method for producing a magnetic alloy according to claim 21 , wherein an average temperature-elevating speed in said heat treatment is 0.1-200° C./minute.
24. The method for producing a magnetic alloy according to claim 13 , wherein a part of Fe is substituted by Ni and/or Co in a proportion of 10 atomic % or less based on Fe.
25. The method for producing a magnetic alloy according to claim 13 , wherein a part of Fe is substituted by at least one element selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, platinum-group elements, Au, Ag, Zn, In, Sn, As, Sb, Bi, Y, N, O and rare earth elements in a proportion of 5 atomic % or less based on Fe.