Soft magnetic alloy and method for producing a soft magnetic alloy
View Patent ↗A soft magnetic alloy is provided that consists essentially of 47 weight percent≦Co≦50 weight percent, 1 weight percent≦V≦3 weight percent, 0 weight percent≦Ni≦0.25 weight percent, 0 weight percent≦C≦0.007 weight percent, 0 weight percent≦Mn≦0.1 weight percent, 0 weight percent≦Si≦0.1 weight percent, at least one of niobium and tantalum in amounts of x weight percent of niobium, y weight percent of tantalum, remainder Fe. The alloy includes 0 weight percent≦x<0.15 weight percent, 0 weight percent≦y≦0.3 weight percent and 0.14 weight percent≦(y+2x)≦0.3 weight percent. The soft magnetic alloy has been annealed at a temperature in the range of 730° C. to 880° C. for a time of 1 to 6 hours and comprises a yield strength in the range of 200 MPa to 450 MPa and a coercive field strength of 0.3 A/cm to 1.5 A/cm.
1. A soft magnetic alloy consisting essentially of 47 weight percent≦Co≦50 weight percent, 1 weight percent≦V≦3 weight percent, 0 weight percent<Ni≦0.25 weight percent, 0 weight percent≦C≦0.007 weight percent, 0 weight percent≦Mn≦0.1 weight percent, 0 weight percent≦Si≦0.1 weight percent, niobium in an amount of x weight percent of niobium, remainder Fe,
wherein Zr is present in an amount of not more than 0.5 weight percent,
wherein 0.07 weight percent≦x<0.125 weight percent,
wherein the alloy has been annealed at a temperature in the range of 730° C. to 880° C. for a time of 1 to 6 hours,
wherein the soft magnetic alloy has a yield strength (0.2% strain) in the range of 200 MPa to 450 MPa and has a coercive field strength of 0.3 A/cm to 1.5 A/cm, and
wherein the soft magnetic alloy has a resistivity of at least 0.4 μΩm or an induction B (8 A/m) of at least 2.12 T, or both.
2. The soft magnetic alloy according to claim 1 , wherein 0 weight percent≦Ni≦0.20 weight percent.
3. The soft magnetic alloy according to claim 1 , wherein 0 weight percent≦C≦0.005 weight percent.
4. The soft magnetic alloy according to claim 3 , wherein 0 weight percent≦C<0.003 weight percent.
5. The soft magnetic alloy according to claim 1 , wherein the alloy has a nickel content such that 0 weight percent<Ni≦0.2 weight percent.
6. The soft magnetic alloy according to claim 1 , wherein the alloy has a manganese content such that 0 weight percent<Mn≦0.07 weight percent.
7. The soft magnetic alloy according to claim 1 , wherein the alloy has a silicon content such that 0 weight percent<Si≦0.05 weight percent.
8. The soft magnetic alloy according to claim 1 , wherein the soft magnetic alloy has a resistivity of at least 0.4 μΩm.
9. The soft magnetic alloy according to claim 1 , wherein the soft magnetic alloy has an induction B (8 A/m) of at least 2.12 T.
10. The soft magnetic alloy according to claim 1 , wherein the soft magnetic alloy has a composition which is selected so that the yield strength of the soft magnetic alloy is adjustable over a range of at least 130 MPa after having been annealed at 750° C. or at 871° C.
11. The soft magnetic alloy according to claim 1 , wherein in an annealed state, the soft magnetic alloy has a yield strength (0.2% strain) that lies within ±10% of a linear function of yield strength (0.2% strain) against annealing temperature.
12. The soft magnetic alloy according to claim 1 , wherein the soft magnetic alloy has a yield strength (0.2% strain) that is a linear function of annealing temperature over an annealing temperature range of 730° C. to 900° C.
13. The soft magnetic alloy according to claim 12 , wherein the soft magnetic alloy has a yield strength (0.2% strain) that is a linear function of annealing temperature over an annealing temperature range of 740° C. to 865° C.
14. A stator for an electric motor comprising the soft magnetic alloy according to claim 1 .
15. A rotor for an electric motor comprising the soft magnetic alloy according to claim 1 .
16. An electric motor comprising a stator and rotor, each comprising a soft magnetic alloy according to claim 1 .
17. A method for manufacturing a rotor for an electric motor comprising providing the soft magnetic alloy according to claim 1 and annealing at a temperature of 730 to 790° C.
18. A method for manufacturing a stator for an electric motor comprising providing the soft magnetic alloy according to claim 1 and annealing at a temperature of 800° C. to 880° C.
19. A method for manufacturing a soft magnetic alloy, comprising:
providing a melt consisting essentially of 47 weight percent≦Co≦50 weight percent, 1 weight percent≦V≦3 weight percent, 0 weight percent≦Ni≦0.25 weight percent, 0 weight percent≦C≦0.007 weight percent, 0 weight percent≦Mn≦0.1 weight percent, 0 weight percent≦Si≦0.1 weight percent, niobium in an amount of x weight percent, remainder Fe,
wherein Zr is present in an amount of not more than 0.5 weight percent,
wherein 0.07 weight percent≦x≦0.125 weight percent;
cooling and solidifying the melt and forming a blank;
hot rolling the blank, followed by
quenching the blank from a temperature above 730° C., followed by
cold rolling the blank, and subsequently
annealing at least a portion of the blank at a temperature in the range of 730° C. to 880° C. and producing a yield strength in the range of 200 MPa to 450 MPa and a coercive field strength of 0.3 A/cm to 1.5 A/cm, and
wherein the soft magnetic alloy has a resistivity of at least 0.4 μΩm or an induction B (8 A/m) of at least 2.12 T, or both.
20. The method according to claim 19 , wherein at least a portion of the blank is annealed at a temperature in the range of 740° C. to 865° C.
21. The method according to claim 19 , wherein at least a portion of the blank is annealed at a temperature in the range of 730° C. to 790° C. or in the range of 800° C. to 880° C.
22. The method according to claim 19 , wherein the hot rolling of the blank produces a thickness reduction in the blank of 90%.
23. The method according to claim 19 , wherein the hot rolling of the blank includes rolling at a temperature in the range of 1100° C. to 1300° C.
24. The method according to claim 19 , further comprising after hot rolling, cooling the blank and quenching from a temperature of above 730° C. to room temperature or cooling the blank and reheating to a temperature above 730° C. and then quenching to room temperature.
25. The method according to claim 19 , further comprising pickling the blank before cold rolling.
26. The method according to claim 19 , wherein the cold rolling of the blank produces a thickness reduction in the blank of 90%.
27. The method according to claim 19 , wherein after cold rolling, the thickness of the blank lies in the range of 0.3 mm to 0.4 mm.
28. A method for manufacturing a semi-finished part comprising forming a blank according to the method according to claim 19 , and separating a portion of the blank to produce a semifinished part.
29. The method according to claim 28 , further comprising assembling a plurality of semi-finished parts manufactured by the method according to claim 28 and forming a laminated soft magnetic article.