CA1317484C - Glassy metal alloys with perminvar characteristics - Google Patents
Glassy metal alloys with perminvar characteristicsInfo
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- CA1317484C CA1317484C CA000533379A CA533379A CA1317484C CA 1317484 C CA1317484 C CA 1317484C CA 000533379 A CA000533379 A CA 000533379A CA 533379 A CA533379 A CA 533379A CA 1317484 C CA1317484 C CA 1317484C
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/07—Alloys based on nickel or cobalt based on cobalt
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
- H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
- H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
- H01F1/12—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials
- H01F1/14—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of soft-magnetic materials metals or alloys
- H01F1/147—Alloys characterised by their composition
- H01F1/153—Amorphous metallic alloys, e.g. glassy metals
- H01F1/15316—Amorphous metallic alloys, e.g. glassy metals based on Co
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Abstract
ABSTRACT
GLASSY METAL ALLOYS WITH PERMINVAR CHARACTERISTICS
A series of glassy metal alloys with near zero magnetostriction and Perminvar characteristics of relatively constant permeability at low magnetic field excitations and constricted hysteresis loops is disclosed. The glassy alloys have the compositions CoaFebNicMdBeSif where M is at least one member selected from the group consisting of Cr, Mo, Mn and Nb, and "a-t" are in atom percent where "a" ranges from about 66 to 71, "b" ranges from about 2.5 to 4.5, "c" ranges from about 0 to 3, "d" ranges from about 0 to 2 except when M=Mn in which case "d" ranges from about 0 to 4, "e"
ranges from about 6 to 24 and "f" ranges from about 0 to 19, with the proviso that the sum of "a", "b" and "c"
ranges from about 72 to 76 and the sum of "e" and "f"
ranges from about 25 to 27. The glasy alloy has a value of magnetostriction ranging from about - 1x10-6 to about + 1x10-6, a saturation induction ranging from about 0.5 to 1 Tesla, a Curie temperature ranging from about 200 to 450°C and a first crystallization temperature ranging from about 440 to 570°C. The glassy alloy is heat-treated between about 50 and 110°C. below its first crystallization temperature for a time period ranging from about 15 to 180 minutes, then cooled to room temperature at a rate slower than about - 60°C/min.
GLASSY METAL ALLOYS WITH PERMINVAR CHARACTERISTICS
A series of glassy metal alloys with near zero magnetostriction and Perminvar characteristics of relatively constant permeability at low magnetic field excitations and constricted hysteresis loops is disclosed. The glassy alloys have the compositions CoaFebNicMdBeSif where M is at least one member selected from the group consisting of Cr, Mo, Mn and Nb, and "a-t" are in atom percent where "a" ranges from about 66 to 71, "b" ranges from about 2.5 to 4.5, "c" ranges from about 0 to 3, "d" ranges from about 0 to 2 except when M=Mn in which case "d" ranges from about 0 to 4, "e"
ranges from about 6 to 24 and "f" ranges from about 0 to 19, with the proviso that the sum of "a", "b" and "c"
ranges from about 72 to 76 and the sum of "e" and "f"
ranges from about 25 to 27. The glasy alloy has a value of magnetostriction ranging from about - 1x10-6 to about + 1x10-6, a saturation induction ranging from about 0.5 to 1 Tesla, a Curie temperature ranging from about 200 to 450°C and a first crystallization temperature ranging from about 440 to 570°C. The glassy alloy is heat-treated between about 50 and 110°C. below its first crystallization temperature for a time period ranging from about 15 to 180 minutes, then cooled to room temperature at a rate slower than about - 60°C/min.
Description
DEsc~IPrIoN 1317~8~
GLASSY METAL ALLOYS WITH PERMINVAR CHARACT~RISTI~
BACKGROUND OF INVENTION
1. Field of Invention This invention relates to glassy metal alloys with Perminvar characteristics that is constant permeabilities at low magnetic field excitations and constricted hysteresis loops. More particularly, this invention provides glassy metal alloys with highly non-linear magnetic properties at low magnetic excitation levels.
GLASSY METAL ALLOYS WITH PERMINVAR CHARACT~RISTI~
BACKGROUND OF INVENTION
1. Field of Invention This invention relates to glassy metal alloys with Perminvar characteristics that is constant permeabilities at low magnetic field excitations and constricted hysteresis loops. More particularly, this invention provides glassy metal alloys with highly non-linear magnetic properties at low magnetic excitation levels.
2. Description of Prior Art The magnetic response, namely magnetic induction caused by magnetic excitation, of a typical ferromagnet, is non-linear characterized by a hysteresis loo~. This loop usually does not allow a relatively constant - permeability near the zero-excitation point. To realize such a feature, so-called Perminvar alloys were developed [see, for exam~le, R. M. Bozorth, Ferromagnetism (Van Nostrand, Co., Inc., New York, 1951) p. 166-180]. These alloys are usually based on crystalline iron-cobalt-nickel system. Typical compositions (weight percent) include 20%Fe-60~Co-20%Ni ~20-60 Perminvar) and 30%Fe-25%Co-45%Ni (45-45 Perminvar). Improvements of the crystalline Perminvar al~oys have been made. Of significance is the addition of molybdenum, as exemplified by the synthesis of 7.5-45-25 Mo-Perminvar (7.5%Mo-45%Ni-25%Co-22.5~Fe). This material, when furnace cooled from 1110C, exhibited a dc coercivity (Hc) of 40 A/m (=0.5 Oe), initial permeability ( ~O) of 100 and the remanence (Br) of 0.75 T.
In the advent of modern electronics technology, it becomes necessary to further improve the Perminvar-like properties. For example, further reduction Hc and increase of ~o would be desirable when an efficient transformer re~uiring low field modulations is needed.
Furthermore, the usual non-linear characteristic of the , --conventional Perminvar alloys cannot be utilized without a large level of excitation of well above 80 A/m (=l Oe). Also desirable in many applications are low ac magnetic losses. One approach to attain these excellent 5 soft magnetic properties is to reduce the materials' magnetostriction values as low as possible.
Saturation magnetostriction As is related to the fractional change in length ~ that occurs in a magnetic material on going from the demagnetized to the saturated, ferromagnetic state. The value of magnetostriction, a dimensionless quantity, is often given in units of microstrains (i.e., a microstrain is a fractional change in length of one part per million).
Ferromagnetic alloys of low magnetostriction are desirable for several interrelated reasons:
1. Soft magnetic properties (low coercivity, high permeability) are generally obtained when both the saturation magnetostriction As and the magnetocrystalline anisotropy K approach zero.
Therefore, given the same anisotropy, alloys of lower magnetostriction will show lower dc coercivities and bigher permeabilities. Such alloys are suitable for various soft magnetic a~plication.
2. Magnetic properties of such zero magnetostrictive materials are insensitive to mechanical strains. When this is the case, there is little need for stress-relief annealing after winding, punching or other physical handling needed to form a device from such material. In contrast, magnetic ~ro~erties of stress-sensitive materials, such as the crystalline alloys, are seriously degraded by sucb cold workin~ and such materials must be carefully annealed.
In the advent of modern electronics technology, it becomes necessary to further improve the Perminvar-like properties. For example, further reduction Hc and increase of ~o would be desirable when an efficient transformer re~uiring low field modulations is needed.
Furthermore, the usual non-linear characteristic of the , --conventional Perminvar alloys cannot be utilized without a large level of excitation of well above 80 A/m (=l Oe). Also desirable in many applications are low ac magnetic losses. One approach to attain these excellent 5 soft magnetic properties is to reduce the materials' magnetostriction values as low as possible.
Saturation magnetostriction As is related to the fractional change in length ~ that occurs in a magnetic material on going from the demagnetized to the saturated, ferromagnetic state. The value of magnetostriction, a dimensionless quantity, is often given in units of microstrains (i.e., a microstrain is a fractional change in length of one part per million).
Ferromagnetic alloys of low magnetostriction are desirable for several interrelated reasons:
1. Soft magnetic properties (low coercivity, high permeability) are generally obtained when both the saturation magnetostriction As and the magnetocrystalline anisotropy K approach zero.
Therefore, given the same anisotropy, alloys of lower magnetostriction will show lower dc coercivities and bigher permeabilities. Such alloys are suitable for various soft magnetic a~plication.
2. Magnetic properties of such zero magnetostrictive materials are insensitive to mechanical strains. When this is the case, there is little need for stress-relief annealing after winding, punching or other physical handling needed to form a device from such material. In contrast, magnetic ~ro~erties of stress-sensitive materials, such as the crystalline alloys, are seriously degraded by sucb cold workin~ and such materials must be carefully annealed.
3. The low dc coercivity of zero magnetostrictive materials carries over to ac operating conditions where again low coercivity and high permeability are realized (provided the magnetocrystalline anisotropy is not too large and the resistivity not too small). AlSo because energy is not lost to mechanical vibrations when the _3_ 1 3 1 7'~ 8~
saturation maganetostriction is zero, the core lo~s of zero magnetostrictive materials can be quite low. Thus, zero magnetostrictive magnetic alloys (of moderate or low magnetocrystalline anisotropy) are useful where low 5 loss and high ac permeability are re~uired. SUCh applications include a variety of tape-wound and laminated core devices, such as power transformers, signal transformers, magnetic recording heads and the like.
saturation maganetostriction is zero, the core lo~s of zero magnetostrictive materials can be quite low. Thus, zero magnetostrictive magnetic alloys (of moderate or low magnetocrystalline anisotropy) are useful where low 5 loss and high ac permeability are re~uired. SUCh applications include a variety of tape-wound and laminated core devices, such as power transformers, signal transformers, magnetic recording heads and the like.
4. Finally, electromagnetic devices containing zero magnetostrictive materials generate no acoustic noise under AC excitation. While this is the reason for the lower core loss mentioned above, it is also a desirable characteristic in itself because it eliminates the hum inherent in many electromagnetic devices.
There are three well-known crystalline alloys of zero magnetostriction (in atom percent, unless otherwise indicated):
(1) Nickel-iron alloys containing approximately 80% nickel (~80 nickel permalloys~);
(2) Cobalt-iron alloys containing ap~roximately 90% cobalt; and (3) Iron-silicon alloys containing approximately 6 wt. % silicon.
Also included in these categories are zero magnetostrictive alloys based on the binaries but with small additions of other elements such as molybdenum, copper or aluminum to provide specific property changes. These include, for example, 4% Mo, 79~ Ni, 17 Fe (sold under the designation Moly Permalloy) for increased resistivity and permeability; permalloy plus varying amounts of copper (sold under the designation Mumetal) for magnetic softness and improved ductility;
and 85 wt. % Fe, 9 wt. % Si, 6 wt. % Al (sold under the designation Sendust) for zero anisotro~y.
The alloys included in category (1) are the most widely used of the three classes listed above because they combine zero magnetostriction with low anisotropy . . .
~4~ 1317~84 and are, therefore, extremely soft magnetically~ that is they have a low coercivity, a high permeability and a low core loss. These permalloys are also relatively soft mechanically and their excellent magnetic 5 pro~erties, achieved by high temperature (above 1000C) anneal, tend to be degraded by relatively mild mechanical shock.
Category (2) alloys such as those based on CogOFe10 have a much higher saturation induction (Bs about 1.9 Tesla) than the permalloys. However, they also have a strong negative magnetocrystalline anisotropy, which prevents them from being good soft magnetic materials.
For example, the initial permeability of CogOFe10 is only about 100 to 200.
Category (3) alloys such as Fe-6 wt~ Si and the related ternary alloy Sendust (mentioned above) also show higher saturation inductions (BS about 1.8 Tesla and 1.1 Tesla, respectively) than the permalloys.
However these alloys are extr-emely brittle and have, therefore, found limited use in powder form only.
Recently both Fe-6.5 wt. % Si lIEEE Trans. MAG-16, 728 (1980)] and Sendust alloys [IEEE Trans. MAG-15, 1149 (1970)] have been made relatively ductile by ra~id solidification. However, compositional dependence of the magnetostriction is very strong in these materials, making difficult precise tayloring of the alloy composition to achieve near-zero maganetostriction.
It is known that magnetocrystalline anisotropy is effectively eliminated in the glassy state. It is therefore, desirable to seek glassy metal alloys of zero magnetostriction. Such alloys might be found near the compositions listed above. Because of the presence of metalloids which tend to reduce the magnetization by dilution and electronic hybridization, however, glassy metal alloys based on the 80 nickel permalloys are either non-magnetic at room temperature or have unacceptably low saturation inductions. For exam~le, the glassy alloy Fe40Ni40P14B6 (the subscripts are in 1317~84 atom percent) has a saturation induction of about 0.8 Tesla, while the glassy alloy Ni49Fe29P14B6Si2 has a saturation induction of about 0.46 Tesla and the glassy alloy Ni80P20 is non-magnetic. No glassy metal alloys 5 haviny a saturation magnetostriction approximately e~ual to zero have yet been found near the iron-rich Sendust composition. A number of near-zero magnetostrictive glassy metal alloys based on the Co-Fe crystalline alloy mentioned above in (2) bave been reported in the literature. These are, for example, Co72Fe3P16B6A13 (AIP Conference Proceedinys, No. 24, pp. 745-746 (1975)) Co70 5Fe4 5Sil5Blo Vol. 14, Japanese Journal of Applied Physics, ~p. 1077-1078 (1975)) C31.2Fe7.8Ni39.0~14Si8 lproceedings of 3rd International Conference on ~apidly Quenched Metals, p. 183, (1979)] and Co74Fe6B20 [IEEE
Trans. MAG-12, 942 (1976)]. However, none of the above-mentioned near-zero magnetostrictive materials show Perminvar-like characteristics. By polishing the surface of a low magnetostrictive glassy ribbon, a surface uniaxial anisotrpy was introduced along the polishing direction which resulted in observation of Perminvar-like Kerr hysteresis loops (Applied Physics Letters, vol. 36, pp. 339-341 (1980). This is only a surface effect and is not of a bulk property of the material, limiting the use of such effect in some selected devices.
Furthermore, to realize the Perminvar pro~erties, the crystalline materials mentioned-above have to be baked for a long time at a given temperature. Typica11y the heat-treatment is performed at 425C for 24 hours.
Obviously it is desirable to heat-treat the materials at a temperature as low as possible and for a duration as short as possiDle.
Clearly desirable are new maynetic materials with various Perminvar characteristics which are suited for modern electronics technology.
There are three well-known crystalline alloys of zero magnetostriction (in atom percent, unless otherwise indicated):
(1) Nickel-iron alloys containing approximately 80% nickel (~80 nickel permalloys~);
(2) Cobalt-iron alloys containing ap~roximately 90% cobalt; and (3) Iron-silicon alloys containing approximately 6 wt. % silicon.
Also included in these categories are zero magnetostrictive alloys based on the binaries but with small additions of other elements such as molybdenum, copper or aluminum to provide specific property changes. These include, for example, 4% Mo, 79~ Ni, 17 Fe (sold under the designation Moly Permalloy) for increased resistivity and permeability; permalloy plus varying amounts of copper (sold under the designation Mumetal) for magnetic softness and improved ductility;
and 85 wt. % Fe, 9 wt. % Si, 6 wt. % Al (sold under the designation Sendust) for zero anisotro~y.
The alloys included in category (1) are the most widely used of the three classes listed above because they combine zero magnetostriction with low anisotropy . . .
~4~ 1317~84 and are, therefore, extremely soft magnetically~ that is they have a low coercivity, a high permeability and a low core loss. These permalloys are also relatively soft mechanically and their excellent magnetic 5 pro~erties, achieved by high temperature (above 1000C) anneal, tend to be degraded by relatively mild mechanical shock.
Category (2) alloys such as those based on CogOFe10 have a much higher saturation induction (Bs about 1.9 Tesla) than the permalloys. However, they also have a strong negative magnetocrystalline anisotropy, which prevents them from being good soft magnetic materials.
For example, the initial permeability of CogOFe10 is only about 100 to 200.
Category (3) alloys such as Fe-6 wt~ Si and the related ternary alloy Sendust (mentioned above) also show higher saturation inductions (BS about 1.8 Tesla and 1.1 Tesla, respectively) than the permalloys.
However these alloys are extr-emely brittle and have, therefore, found limited use in powder form only.
Recently both Fe-6.5 wt. % Si lIEEE Trans. MAG-16, 728 (1980)] and Sendust alloys [IEEE Trans. MAG-15, 1149 (1970)] have been made relatively ductile by ra~id solidification. However, compositional dependence of the magnetostriction is very strong in these materials, making difficult precise tayloring of the alloy composition to achieve near-zero maganetostriction.
It is known that magnetocrystalline anisotropy is effectively eliminated in the glassy state. It is therefore, desirable to seek glassy metal alloys of zero magnetostriction. Such alloys might be found near the compositions listed above. Because of the presence of metalloids which tend to reduce the magnetization by dilution and electronic hybridization, however, glassy metal alloys based on the 80 nickel permalloys are either non-magnetic at room temperature or have unacceptably low saturation inductions. For exam~le, the glassy alloy Fe40Ni40P14B6 (the subscripts are in 1317~84 atom percent) has a saturation induction of about 0.8 Tesla, while the glassy alloy Ni49Fe29P14B6Si2 has a saturation induction of about 0.46 Tesla and the glassy alloy Ni80P20 is non-magnetic. No glassy metal alloys 5 haviny a saturation magnetostriction approximately e~ual to zero have yet been found near the iron-rich Sendust composition. A number of near-zero magnetostrictive glassy metal alloys based on the Co-Fe crystalline alloy mentioned above in (2) bave been reported in the literature. These are, for example, Co72Fe3P16B6A13 (AIP Conference Proceedinys, No. 24, pp. 745-746 (1975)) Co70 5Fe4 5Sil5Blo Vol. 14, Japanese Journal of Applied Physics, ~p. 1077-1078 (1975)) C31.2Fe7.8Ni39.0~14Si8 lproceedings of 3rd International Conference on ~apidly Quenched Metals, p. 183, (1979)] and Co74Fe6B20 [IEEE
Trans. MAG-12, 942 (1976)]. However, none of the above-mentioned near-zero magnetostrictive materials show Perminvar-like characteristics. By polishing the surface of a low magnetostrictive glassy ribbon, a surface uniaxial anisotrpy was introduced along the polishing direction which resulted in observation of Perminvar-like Kerr hysteresis loops (Applied Physics Letters, vol. 36, pp. 339-341 (1980). This is only a surface effect and is not of a bulk property of the material, limiting the use of such effect in some selected devices.
Furthermore, to realize the Perminvar pro~erties, the crystalline materials mentioned-above have to be baked for a long time at a given temperature. Typica11y the heat-treatment is performed at 425C for 24 hours.
Obviously it is desirable to heat-treat the materials at a temperature as low as possible and for a duration as short as possiDle.
Clearly desirable are new maynetic materials with various Perminvar characteristics which are suited for modern electronics technology.
-6- 13~7~84 SUMMARY OF INVENTION
-In accordance with the invention, there is ~rovided a magnetic alloy that is at least 70~ glassy and which has a low magnetostriction and Perminvar characteristics 5 of relatively constant permeability at low magnetic field excitations and a constricted hysteresis loop in addition to excellent soft magnetic properties. The glassy metal alloy has the composition CoaFebNic~ldBeSif where M is at least one number selected from the group 10 consisting of Cr, Mo~ Mn and Nb, "a-f" are in atom percent and the sum of "a-f" equals 100, a ranges from about 66 to 71, "b" eanges from about 2.5 to 4.5, "c"
ranges from about 0 to 3, "d~ ranges from about 0 to 2 exce~t when M=Mn in which case "d" ranges from about 0 to 4, ~e" ranges from about 6 to 24 and "f" ranges from about 0 to 19, with the proviso that the sum of ~a~, "b~, and ~c" ranges from about 72 to 76 and the sum of "e~ and "f~ ranges from about 25 to 27. The ylassy alloy has a value of magnetostriction ranging from about 20 ~ lx10 6 to + lx10 6, a saturation induction ranging from about 0.5 to 1 Tesla, a Curie temperature ranging from about 200 to 450C and a first crystallization temperature ranging from about 440 to 570C. The glassy alloy is heat-treated by heating it to a temperature 25 between about 50 and 110C below its first crystallization temperature for a time period ranging from 15 to 180 min., and then cooling the alloy at a rate slower than about - 60C/min.
DETAILED DESCRIPTION OF THE INVENTION
The glassy alloy is heat-treated at a temperature Ta for a duration of time ta~ where ~ TC-a = (TCl-Ta) is between 50 and about 110C; ant ta is between about 15 and 120 minutes, followed by cooling of the material at a rate slower than about -10C/min. The choice of Ta and ta should exclude the case that ~ TC_a ~ 50C and ta ~ 15 minutes because such combination sometimes results in crystallization of the glassy alloy.
1317~8~
The purity of the above composition is that foun~
in normal commercial practice. However, it would be appreciated that the metal ~l in the alloys of the invention may be replaced by at least one other element 5 such as vanadium, tungsten, tantalum, titanium, zirconium and hafnium, and up to about 4 atom percent of Si may be replaced by carbon, aluminum or germanium without significantly degrading the desicable magnetic properties of these alloys.
Examples of near-zero magnetostrictive glassy metal alloys of the invention include Co70.5Fe4.5B15Si10, 69.0Fe4.1~il.4M1 5Bl2si Co65 7Fe4 4Ni2 gMo2Bllsil4~ CO69.2Fe3-8Mo2B8 17 Co67 5Fe4 5Ni3 oB8Sil7~ C70.g8Fe4.1B8S 17' Co69.9Fe4.lMnl.oB8sil7~ Co6g.oFe4.oMn2B8si 68.0 e4~oMn3B8si17~ Co67 1Fe3 9Mn4B8si17~
68-0 4.0 n2CrlBgSil7~ Co69 OFe4 OCr2B8sil7, Co69 OFe4 oNb2B8Si17~ C68.2Fe3.8Mnl 12 15 Co67 7Fe3 3Mn2B12Sil5~ C67.8Fe4.2 1 12 15 C67 8Fe4 2CrlB12Sil5~ CO67.0Fe4.0C 2 12 15 Co66 1Fe3 9Cr3B12sils~C68.5Fe2.5Mn4 10 15 CO65.7Fe4.4Ni2.gMO2B23C2 and Co68 6Fe4 4Mo2Ge4B2l.
These alloys possess saturation induction (Bs) between O.S and 1 Tesla, Curie temperature between 200 and 450C
and excellent ductility. Some magnetic and thermal properties of these and some of other near-zero magnetostrictive alloys of the present invention are listed in Table I.
TABLE I
Saturation induction (Bs), Curie temperature ( ~ f)~ saturation magnetostriction I As) and the first - crystallization temperature (TCl) of near -zero magnetostrictive alloys of the present invention.
1317 ~8~
Compositions Co Fe Ni ~1 B Si 70.5 4.5 - - 15 10 69.0 4.1 1.4 M~=1.5 12 12 5 65.7 4.4 2.9 M~=2 11 14 68.2 3.8 - Mn=l 12 15 67.7 3.3 - Mn=2 12 15 67.8 4.2 - M~=l 12 15 67.8 4.2 - Cr=l 12 15 10 69.2 3.8 _ M~=2 8 17 67.5 4.5 3.0 - 8 17 70.98 4.1 - - 8 17 69.9 4.1 - Mn=l 8 17 69.0 4.0 - Mn=2 8 17 15 68.0 4.0 - Mn=3 8 17 67.1 3.9 - Mn=4 8 17 69.0 4.0 - Cr=2 8 17 68.0 4.0 - Mn=2,Cr=1 8 17 69.0 4.0 - ~b=2 8 17 20 65.7 4.4 2.9 Mo=2 23 C=3*
65.7 4.4 2.9 Moc2 23 2 69.5 4.1 1.4 - 6 19 58.6 4.4 - Mb--2 21 Ge=4*
70.5 4.5 - - 24 Ge=l*
25 67.0 4.0 - Cr=2 12 15 69.2 3.8 - Mb=2 10 15 68.1 4.0 1.4 Mo=1.5 8 17 69.0 3.0 - Mn=3 10 15 68.5 2.5 - Mn=4 10 15 30 68.8 4.2 - Cr=2 10 15 * All Si content is replaced by the indicated element and amount.
- -` 1317~84 g B~(Tesla) ~ f(C) A s(10 6) T~1(C) 0.82 422 -0.3 517 0.73 324 0 520 0.77 246 0 530 5 0.70 266 +0.4 558 0.71 246 +0.4 560 0.62 227 +0.4 556 0.64 234 +0.6 561 0.67 295 +0.5 515 10 0 73 32g +0.5 491 0.77 343 -0.4 490 0.77 331 -0.5 493 0.75 312 +0.8 502 0.74 271 +0.9 507 15 0 74 269 -0.8 512 0.63 261 +0.2 503 0.69 231 +0.7 511 0.62 256 +0.4 541 0.76 393 o 500 0.79 402 0 512 0.73 316 -0.1 443 0.77 365 0 570 0.99 451 -0.4 494 0.57 197 +0.4 480 25 0.72 245 +0.4 541 0.67 276 +0.4 512 0.79 305 +1.1 544 0.78 273 +0.4 548 0.69 261 +0.4 540 Figure 1 illustrates the B(induction)-H(applied field) hysteresis loops for a near-zero magnetostrictive C67 8Fe4 2crlB12sil5 glassy alloy heat-treated at Ta =
460C (A), Ta = 480C (B) and Ta = 500C (C) for 15 minutes, followed by cooling at a rate of about -5C/min. The constricted B-H loops of Figs lB and lC
are characteristic of the materials with Perminvar-like properties, whereas the B-H loop of Fig. lA corresponds ~:
... . .
--lo- 1 31 7~8~
to that of a typical soft ferromagnet. As evidenced in Figure 1, the choice of the heat-treatment temperature Ta is very important in obtaining the Perminvar characteristics in the glassy alloys of the peresent invention. Table II summarizes the heat-treatment conditions for some of these alloys and some of the resultant magnetic properties.
Table II
Heat-treatment temperature (Ta) and duration ~ta) to obtain Perminvar characteristics in the glassy alloys of the present invention. ~ TC-a is equal to (TCl ~Ta)~ Cooling rate is about -5C/min. unless stated otherwise. The quantity ~O is the initial dc permeability and Hc is the coercivity obtained after the heat-treatment.
Com~ositions Co Fe Ni M - B Si 70.5 4.5 - - 15 10 70.5 4.5 - - 15 10 70.5 4.5 - - 15 10 69.0 4.1 1.4Mo=1.5 12 12 69.0 4.1 1.4Mo=1.5 12 12 65.7 4.4 2.9Mo=2 11 14 68.2 3.8 - Mn=l 12 15 68.2 3.8 - Mn=l 12 15 67.7 3.3 - Mn=2 12 15 67.7 3.3 - Mn=2 12 15 67.8 4.2 - Mo=l 12 15 67.8 4.2 - Cr=l 12 15 67.8 4.2 - Cr=l 12 15 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mos2 8 17 69.2 3.8 - Mn=2 8 17 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 17 131~
Compositions Co Fe Ni M ~ ~i 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 17 70.98 4.1 - - 8 17 70.98 4.1 - - 8 17 69.9 4.1 - Mn=l 8 17 69.9 4.1 - Mn=l 8 11 69.0 4.0 - Mn=2 8 17 69.0 4.0 - Mn=2 8 17 68.0 4.0 - Mn=3 8 17 68.0 4.0 - Mn=3 8 17 67.1 3,9 - Mn-4 8 17 69.0 4.0 - Cr=2 8 17 69.0 4.0 - Cr=2 8 17 68.0 4.0 -Mn=2,Cr=1 8 17 68.0 4.0 -Mn=2,Cr=1 8 17 69.0 4.0 - Nb=2 8 17 68.1 4.0 1.4Mo=1.5 8 17 68.1 4.0 1.4Mo=1.5 8 17 65.7 4.4 2.9Mo=2 23 C=3*
65.7 4.4 2.9Mo=2 23 2 69.5 4.1 1.4 - 6 19 68.5 4.4 - Mo=2 21 Ge=4*
70.5 4.5 - - 24 Ge=l*
69.2 3.8 - Mo=2 10 15 69.2 3.8 - Mo=2 10 15 69.0 3.0 - Mo=3 10 15 68.5 2.5 - Mn=4 10 lS
68.8 4.2 - Cr=2 10 15 * All of Si content is replaced by the indicated element.
-12-1317~8~
T~ (C) t~(min .) ~ Tr_~ (C) Hr (A/m) ~ ~
460 lS 57 3.47,900 460 lS** 57 3.1S,700 460 lS*** 57 1.47,600 430 120 90 1.24,000 430 150 90 3.64,000 420 180 100 6.412,250 420 lS 110 4.033,000 480 15 78 0.2019,000 500 15 58 7.613,000 480 15 80 0.2022,000 500 15 60 0.2022,000 500 15 56 0.4490,000 480 15 81 0.2050,000 500 15 61 0.4430,000 460 15 55 4.29,700 460 30 55 4.910,000 460 45 55 4.58,000 460 90 55 5.07,500 460 105 55 3.97,900 380 45 111 4.712,700 380 60 111 4.59,600 380 90 111 3.611,500 380 105 111 5.015,800 420 15 71 3.67,200 400 15 90 7.05,000 420 lS 70 2.02,400 400 15 93 1.72,500 420 15 73 0.843,600 400 15 102 3.213,000 420 15 82 0.985,00~
400 15 107 2.029,000 420 15 87 3.321,500 420 15 92 0.7015,800 420 15 83 0.8024,000 440 lS 63 0.8421,500 420 15 91 1.431,500 440 lS 71 1.124,000 -13- 1317~8~
T~(C) t?(min.) ~ T~_a(C) Hr(A/m)~o 440 15 101 3.428,700 440 15 72 2.935,800 46Q 15 52 3.619,300 440 15 60 5.6 2,300 450 15 62 10.4 8,000 380 15 63 12 3,300 480 15 90 5.217,000 450 60 91 1.521,000 460 60 81 1.619,300 440 15 104 1.217,500 440 15 108 1.223,000 460 15 80 0.820, oao This table teaches the importance of the quantity ~ Tc a being between about 50 and 110C and relatively slow cooling rates after the heat-treatments at temperature Ta and for the duration ta. It is also noted that ~O values are higher and the Hc values are lower than those of prior art materials. For example, a properly heat-treated (Ta = 460C; ta = 15 min.) 67.8 e4.2crlB12sils glassy alloy exhibits ~ = 50 ooo and Hc = 0.2 A/m whereas one of the improved prior art ,alloy, namely 7.5-45-25 Mo-Perminvar, gives ~O = 100 and Hc = 40 A/m when furnace cooled from 1100C and gives ~O = 3,500 when quenched from 600C.
In many magnetic applications, lower magnetostriction is desirable. For some applications, however, it may be desirable or acceptable to use materials with a small positive or negative magnetostriction. Such near-zero magnetostrictive glassy metal alloys are obtained for a, b, c in the ranges of about 66 to 71, 2.5 to 4.5 and 0 to 3 atom percent respectively, with the proviso that the sum of a, b, and c ranges between 72 and 76 atom percent. The absolute value of saturation magnetostriction ¦ ~sl f these glassy alloys is less than about lxlO 6 (i.e. the ', ,A~
131 7 18~
saturation magnetostriction ranges from about -lx10-6 to +lx10-6 or from -1 to +1 microstrains~.
The glassy alloys of the invention are conveniently prepared by techniques readily available elsewhere; see e.g. US Patent No. 3,845,805 issued November 5, 1974 and No. 3,856,513 issued December 24, 1974. In general, the glassy alloys, in the form of continuous ribbon, wire, etc., are rapidly quenched from a melt of the desired composition at a rate of at least about 105 K/sec.
A metalloid content of boron and silicon in the range of about 25 to 27 atom percent of the total alloy composition is sufficient for glass formation with boron ranging from about 6 to 24 atom percent. It is prefered, however, that the content of metal M, i.e. the quantity d does not exceed very much from about 2 atom percent except when M=Mn to maintain a reasonably high Curie temperature t> 200C).
In addition to the highly non-linear nature of the glassy Perminvar alloys of the present invention, these alloys exhibit high permeabilities and low core loss at high frequencies. Some examples of these features are given in Table III.
Table III
Core loss (L) and impedance permeability ( ~) at f=50 kHz and induction level of 0.1 Tesla for some of the glassy Perminvar-like alloys of the present invention. Ta and ta are heat-treatment temperature and time. Cooling after the heat-treatment is about -5C/min., unless otherwise stated.
-15- 1317~
Compositions Co Fe Ni M B ~i 70.5 4.5 - - 15 10 70.5 4.5 - - 15 10 70.5 4.5 - - 15 10 69.0 4.1 1.4Mo=l.S 12 12 65.7 4.4 2.9Mo=2 11 14 68.2 3.8 - Mn=l 12 15 68.2 3.8 - Mn=l 12 15 67.7 3.3 - Mn~2 12 15 67.7 3.3 - Mn=2 12 15 67.8 4.2 - Mo=l 12 15 67.8 4.2 - Cr=l 12 lS
67.8 4.2 - Cr=l 12 15 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 L7 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 17 70.9 4.1 - - 8 17 70.98 4.1 - - 8 17 69.9 4.1 - Mn=l 8 17 69.9 4.1 - Mn=l 8 17 69.0 4.0 - Mn=2 8 17 69.0 4.0 - Mn=2 8 17 68.0 4.0 - Mn=3 8 17 68.0 4.0 - Mn=3 8 17 67.1 3.9 - Mn=4 8 17 69.0 4.0 - Cr-2 8 17 69.0 4.0 - Cr=2 8 17 68.0 4.0 -Mn=2, Cr=l 8 17 ~68.0 4.0 -Mn=2, Cr=l 8 17 69.1 4.0 - Nb=2 8 17 68.1 4.0 1.4Mo=1.5 8 17 ,~
-~ -16- 1317~8~
Co Fe Ni M B Si 68.1 4.0 1.4Mo=1.5 8 17 65.7 4.4 2.7Mo~2 23 C=3*
65.7 4.4 2.9Mo~2 23 2 68.6 4.4 - Mo-2 21 Ge=4*
69.2 3.8 - Mo=2 10 15 69.0 3.0 - Mn=3 10 15 68.5 2.5 - Mn=4 10 15 68.8 4.2 - Cr=2 10 15 * All of Si content is replaced by the indicated element.
.
-- 1317~
T~(C) t~(min.) L(W/kg) 460 15 352,300 460 15** 392,000 460 15*** 143,400 430 120 142,800 420 15 6.76,000 480 15 4.614,000 500 15 4.4~,300 480 15 4.017,600 500 15 4.517,000 500 15 4.027,600 480 15 4.024,700 500 15 3.722,500 460 15 9.05,400 460 30 6.314,900 460 45 6.613,800 460 90 6.714,400 460 105 6.914,800 380 45 193,000 380 60 202,800 380 90 212,900 ~ 380 105 182,900 420 15 223,000 400 15 312,400 420 15 152,000 400 15 232,800 420 15 162,700 400 15 113,800 420 15 113,800 400 15 8.05,500 420 15 105,200 420 15 5.79,250 420 15 5.512,500 440 15 4.713,200 420 15 4.810,000 440 15 4.710,500 440 15 4.211,200 440 15 6.68,200 -18- 1 3 1 7 ~ ~ 'L~
Ta(C) t~(min.) L(W/kg)~ _ 460 15 7.27,100 440 15 20 2,000 450 15 27 2,800 480 15 9.75,200 450 60 9.19,600 460 60 10 7,700 440 15 8.3~,500 440 15 8.38,200 460 15 5.710,300 ** Cooling rate Y -3C/min.
*** Cooling rate ~ -60C/min.
EXAMPLES
1. Sample Preparation The glassy alloys listed in Tables I-III were rapidly quenched (about 106 K/sec) from the melt following the techniques taught by Chen and Polk in U.S
Patent 3,856,513. The resu]ting ribbons, typically 25 to 30 ~m thick and 0.5 to 2.5 cm wide, were determined to be free of significant crystallinity by X-ray diffractometry (using CuK radiation) and scanning calorimetry. Ribbons of the glassy metal alloys were strong, shiny, hard and ductile.
2 Magnetic Measurements .
Continuous ribbons of the glassy metal alloys prepared in accordance with the procedure described in Example I were wound onto bobbins (3.8 cm O.D.) to form closed-magnetic-path toroidal samples. Each sample contained from 1 to 3 9 of ribbon. Insulated primary and secondary windings (numbering at least 10 each) were applied to the toroids. These samples were used to obtain hysteresis loops (coercivity and remanence) and initial permeability with a commercial curve tracer and core loss (IEEE Standard 106-1972).
The saturation magnetization, Ms~ of each sample, was measured with a commercial vibrating sample . , -lg- 1~17~
magnetometer (Princeton Applied Research). In this case, the ribbon was cut into sevecal small squares (approximately 2 mm x 2 mm). These wer~ randomly oriented about their normal direction, their plane being parallel to the applied field (0 to 720 kA/m. The saturation induction Bs (=4 ~MSD) was then calculated by using the measured mass density D.
The ferromagnetic Curie temperature ( ~f) was measured by inductance method and also monitored by differential scanning calorimetry, which was used primarily to determine the crystallization temperatures.
Magnetostriction measurements employed metallic strain gauges (BLH Electronics), which were bonded (Eastman - 910 Cement) between two short lengths of ribbon. The ribbon axis and gauge axis were parallel.
The magnetostriction was determined as a function of applied field from the longitudinal s~rain in the parallel ( ~Q/ Q) ~ and perpendicular ( ~ Q/Q) 1 in-plain fields, according to the formula ~ = 2/3 ~(QQ/Q)~
- ( ~Q/Q) 1 ]
Having thus described the invention in rather full detail, it will be understood that this detail need not be strictly adhered to but that further changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.
-In accordance with the invention, there is ~rovided a magnetic alloy that is at least 70~ glassy and which has a low magnetostriction and Perminvar characteristics 5 of relatively constant permeability at low magnetic field excitations and a constricted hysteresis loop in addition to excellent soft magnetic properties. The glassy metal alloy has the composition CoaFebNic~ldBeSif where M is at least one number selected from the group 10 consisting of Cr, Mo~ Mn and Nb, "a-f" are in atom percent and the sum of "a-f" equals 100, a ranges from about 66 to 71, "b" eanges from about 2.5 to 4.5, "c"
ranges from about 0 to 3, "d~ ranges from about 0 to 2 exce~t when M=Mn in which case "d" ranges from about 0 to 4, ~e" ranges from about 6 to 24 and "f" ranges from about 0 to 19, with the proviso that the sum of ~a~, "b~, and ~c" ranges from about 72 to 76 and the sum of "e~ and "f~ ranges from about 25 to 27. The ylassy alloy has a value of magnetostriction ranging from about 20 ~ lx10 6 to + lx10 6, a saturation induction ranging from about 0.5 to 1 Tesla, a Curie temperature ranging from about 200 to 450C and a first crystallization temperature ranging from about 440 to 570C. The glassy alloy is heat-treated by heating it to a temperature 25 between about 50 and 110C below its first crystallization temperature for a time period ranging from 15 to 180 min., and then cooling the alloy at a rate slower than about - 60C/min.
DETAILED DESCRIPTION OF THE INVENTION
The glassy alloy is heat-treated at a temperature Ta for a duration of time ta~ where ~ TC-a = (TCl-Ta) is between 50 and about 110C; ant ta is between about 15 and 120 minutes, followed by cooling of the material at a rate slower than about -10C/min. The choice of Ta and ta should exclude the case that ~ TC_a ~ 50C and ta ~ 15 minutes because such combination sometimes results in crystallization of the glassy alloy.
1317~8~
The purity of the above composition is that foun~
in normal commercial practice. However, it would be appreciated that the metal ~l in the alloys of the invention may be replaced by at least one other element 5 such as vanadium, tungsten, tantalum, titanium, zirconium and hafnium, and up to about 4 atom percent of Si may be replaced by carbon, aluminum or germanium without significantly degrading the desicable magnetic properties of these alloys.
Examples of near-zero magnetostrictive glassy metal alloys of the invention include Co70.5Fe4.5B15Si10, 69.0Fe4.1~il.4M1 5Bl2si Co65 7Fe4 4Ni2 gMo2Bllsil4~ CO69.2Fe3-8Mo2B8 17 Co67 5Fe4 5Ni3 oB8Sil7~ C70.g8Fe4.1B8S 17' Co69.9Fe4.lMnl.oB8sil7~ Co6g.oFe4.oMn2B8si 68.0 e4~oMn3B8si17~ Co67 1Fe3 9Mn4B8si17~
68-0 4.0 n2CrlBgSil7~ Co69 OFe4 OCr2B8sil7, Co69 OFe4 oNb2B8Si17~ C68.2Fe3.8Mnl 12 15 Co67 7Fe3 3Mn2B12Sil5~ C67.8Fe4.2 1 12 15 C67 8Fe4 2CrlB12Sil5~ CO67.0Fe4.0C 2 12 15 Co66 1Fe3 9Cr3B12sils~C68.5Fe2.5Mn4 10 15 CO65.7Fe4.4Ni2.gMO2B23C2 and Co68 6Fe4 4Mo2Ge4B2l.
These alloys possess saturation induction (Bs) between O.S and 1 Tesla, Curie temperature between 200 and 450C
and excellent ductility. Some magnetic and thermal properties of these and some of other near-zero magnetostrictive alloys of the present invention are listed in Table I.
TABLE I
Saturation induction (Bs), Curie temperature ( ~ f)~ saturation magnetostriction I As) and the first - crystallization temperature (TCl) of near -zero magnetostrictive alloys of the present invention.
1317 ~8~
Compositions Co Fe Ni ~1 B Si 70.5 4.5 - - 15 10 69.0 4.1 1.4 M~=1.5 12 12 5 65.7 4.4 2.9 M~=2 11 14 68.2 3.8 - Mn=l 12 15 67.7 3.3 - Mn=2 12 15 67.8 4.2 - M~=l 12 15 67.8 4.2 - Cr=l 12 15 10 69.2 3.8 _ M~=2 8 17 67.5 4.5 3.0 - 8 17 70.98 4.1 - - 8 17 69.9 4.1 - Mn=l 8 17 69.0 4.0 - Mn=2 8 17 15 68.0 4.0 - Mn=3 8 17 67.1 3.9 - Mn=4 8 17 69.0 4.0 - Cr=2 8 17 68.0 4.0 - Mn=2,Cr=1 8 17 69.0 4.0 - ~b=2 8 17 20 65.7 4.4 2.9 Mo=2 23 C=3*
65.7 4.4 2.9 Moc2 23 2 69.5 4.1 1.4 - 6 19 58.6 4.4 - Mb--2 21 Ge=4*
70.5 4.5 - - 24 Ge=l*
25 67.0 4.0 - Cr=2 12 15 69.2 3.8 - Mb=2 10 15 68.1 4.0 1.4 Mo=1.5 8 17 69.0 3.0 - Mn=3 10 15 68.5 2.5 - Mn=4 10 15 30 68.8 4.2 - Cr=2 10 15 * All Si content is replaced by the indicated element and amount.
- -` 1317~84 g B~(Tesla) ~ f(C) A s(10 6) T~1(C) 0.82 422 -0.3 517 0.73 324 0 520 0.77 246 0 530 5 0.70 266 +0.4 558 0.71 246 +0.4 560 0.62 227 +0.4 556 0.64 234 +0.6 561 0.67 295 +0.5 515 10 0 73 32g +0.5 491 0.77 343 -0.4 490 0.77 331 -0.5 493 0.75 312 +0.8 502 0.74 271 +0.9 507 15 0 74 269 -0.8 512 0.63 261 +0.2 503 0.69 231 +0.7 511 0.62 256 +0.4 541 0.76 393 o 500 0.79 402 0 512 0.73 316 -0.1 443 0.77 365 0 570 0.99 451 -0.4 494 0.57 197 +0.4 480 25 0.72 245 +0.4 541 0.67 276 +0.4 512 0.79 305 +1.1 544 0.78 273 +0.4 548 0.69 261 +0.4 540 Figure 1 illustrates the B(induction)-H(applied field) hysteresis loops for a near-zero magnetostrictive C67 8Fe4 2crlB12sil5 glassy alloy heat-treated at Ta =
460C (A), Ta = 480C (B) and Ta = 500C (C) for 15 minutes, followed by cooling at a rate of about -5C/min. The constricted B-H loops of Figs lB and lC
are characteristic of the materials with Perminvar-like properties, whereas the B-H loop of Fig. lA corresponds ~:
... . .
--lo- 1 31 7~8~
to that of a typical soft ferromagnet. As evidenced in Figure 1, the choice of the heat-treatment temperature Ta is very important in obtaining the Perminvar characteristics in the glassy alloys of the peresent invention. Table II summarizes the heat-treatment conditions for some of these alloys and some of the resultant magnetic properties.
Table II
Heat-treatment temperature (Ta) and duration ~ta) to obtain Perminvar characteristics in the glassy alloys of the present invention. ~ TC-a is equal to (TCl ~Ta)~ Cooling rate is about -5C/min. unless stated otherwise. The quantity ~O is the initial dc permeability and Hc is the coercivity obtained after the heat-treatment.
Com~ositions Co Fe Ni M - B Si 70.5 4.5 - - 15 10 70.5 4.5 - - 15 10 70.5 4.5 - - 15 10 69.0 4.1 1.4Mo=1.5 12 12 69.0 4.1 1.4Mo=1.5 12 12 65.7 4.4 2.9Mo=2 11 14 68.2 3.8 - Mn=l 12 15 68.2 3.8 - Mn=l 12 15 67.7 3.3 - Mn=2 12 15 67.7 3.3 - Mn=2 12 15 67.8 4.2 - Mo=l 12 15 67.8 4.2 - Cr=l 12 15 67.8 4.2 - Cr=l 12 15 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mos2 8 17 69.2 3.8 - Mn=2 8 17 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 17 131~
Compositions Co Fe Ni M ~ ~i 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 17 70.98 4.1 - - 8 17 70.98 4.1 - - 8 17 69.9 4.1 - Mn=l 8 17 69.9 4.1 - Mn=l 8 11 69.0 4.0 - Mn=2 8 17 69.0 4.0 - Mn=2 8 17 68.0 4.0 - Mn=3 8 17 68.0 4.0 - Mn=3 8 17 67.1 3,9 - Mn-4 8 17 69.0 4.0 - Cr=2 8 17 69.0 4.0 - Cr=2 8 17 68.0 4.0 -Mn=2,Cr=1 8 17 68.0 4.0 -Mn=2,Cr=1 8 17 69.0 4.0 - Nb=2 8 17 68.1 4.0 1.4Mo=1.5 8 17 68.1 4.0 1.4Mo=1.5 8 17 65.7 4.4 2.9Mo=2 23 C=3*
65.7 4.4 2.9Mo=2 23 2 69.5 4.1 1.4 - 6 19 68.5 4.4 - Mo=2 21 Ge=4*
70.5 4.5 - - 24 Ge=l*
69.2 3.8 - Mo=2 10 15 69.2 3.8 - Mo=2 10 15 69.0 3.0 - Mo=3 10 15 68.5 2.5 - Mn=4 10 lS
68.8 4.2 - Cr=2 10 15 * All of Si content is replaced by the indicated element.
-12-1317~8~
T~ (C) t~(min .) ~ Tr_~ (C) Hr (A/m) ~ ~
460 lS 57 3.47,900 460 lS** 57 3.1S,700 460 lS*** 57 1.47,600 430 120 90 1.24,000 430 150 90 3.64,000 420 180 100 6.412,250 420 lS 110 4.033,000 480 15 78 0.2019,000 500 15 58 7.613,000 480 15 80 0.2022,000 500 15 60 0.2022,000 500 15 56 0.4490,000 480 15 81 0.2050,000 500 15 61 0.4430,000 460 15 55 4.29,700 460 30 55 4.910,000 460 45 55 4.58,000 460 90 55 5.07,500 460 105 55 3.97,900 380 45 111 4.712,700 380 60 111 4.59,600 380 90 111 3.611,500 380 105 111 5.015,800 420 15 71 3.67,200 400 15 90 7.05,000 420 lS 70 2.02,400 400 15 93 1.72,500 420 15 73 0.843,600 400 15 102 3.213,000 420 15 82 0.985,00~
400 15 107 2.029,000 420 15 87 3.321,500 420 15 92 0.7015,800 420 15 83 0.8024,000 440 lS 63 0.8421,500 420 15 91 1.431,500 440 lS 71 1.124,000 -13- 1317~8~
T~(C) t?(min.) ~ T~_a(C) Hr(A/m)~o 440 15 101 3.428,700 440 15 72 2.935,800 46Q 15 52 3.619,300 440 15 60 5.6 2,300 450 15 62 10.4 8,000 380 15 63 12 3,300 480 15 90 5.217,000 450 60 91 1.521,000 460 60 81 1.619,300 440 15 104 1.217,500 440 15 108 1.223,000 460 15 80 0.820, oao This table teaches the importance of the quantity ~ Tc a being between about 50 and 110C and relatively slow cooling rates after the heat-treatments at temperature Ta and for the duration ta. It is also noted that ~O values are higher and the Hc values are lower than those of prior art materials. For example, a properly heat-treated (Ta = 460C; ta = 15 min.) 67.8 e4.2crlB12sils glassy alloy exhibits ~ = 50 ooo and Hc = 0.2 A/m whereas one of the improved prior art ,alloy, namely 7.5-45-25 Mo-Perminvar, gives ~O = 100 and Hc = 40 A/m when furnace cooled from 1100C and gives ~O = 3,500 when quenched from 600C.
In many magnetic applications, lower magnetostriction is desirable. For some applications, however, it may be desirable or acceptable to use materials with a small positive or negative magnetostriction. Such near-zero magnetostrictive glassy metal alloys are obtained for a, b, c in the ranges of about 66 to 71, 2.5 to 4.5 and 0 to 3 atom percent respectively, with the proviso that the sum of a, b, and c ranges between 72 and 76 atom percent. The absolute value of saturation magnetostriction ¦ ~sl f these glassy alloys is less than about lxlO 6 (i.e. the ', ,A~
131 7 18~
saturation magnetostriction ranges from about -lx10-6 to +lx10-6 or from -1 to +1 microstrains~.
The glassy alloys of the invention are conveniently prepared by techniques readily available elsewhere; see e.g. US Patent No. 3,845,805 issued November 5, 1974 and No. 3,856,513 issued December 24, 1974. In general, the glassy alloys, in the form of continuous ribbon, wire, etc., are rapidly quenched from a melt of the desired composition at a rate of at least about 105 K/sec.
A metalloid content of boron and silicon in the range of about 25 to 27 atom percent of the total alloy composition is sufficient for glass formation with boron ranging from about 6 to 24 atom percent. It is prefered, however, that the content of metal M, i.e. the quantity d does not exceed very much from about 2 atom percent except when M=Mn to maintain a reasonably high Curie temperature t> 200C).
In addition to the highly non-linear nature of the glassy Perminvar alloys of the present invention, these alloys exhibit high permeabilities and low core loss at high frequencies. Some examples of these features are given in Table III.
Table III
Core loss (L) and impedance permeability ( ~) at f=50 kHz and induction level of 0.1 Tesla for some of the glassy Perminvar-like alloys of the present invention. Ta and ta are heat-treatment temperature and time. Cooling after the heat-treatment is about -5C/min., unless otherwise stated.
-15- 1317~
Compositions Co Fe Ni M B ~i 70.5 4.5 - - 15 10 70.5 4.5 - - 15 10 70.5 4.5 - - 15 10 69.0 4.1 1.4Mo=l.S 12 12 65.7 4.4 2.9Mo=2 11 14 68.2 3.8 - Mn=l 12 15 68.2 3.8 - Mn=l 12 15 67.7 3.3 - Mn~2 12 15 67.7 3.3 - Mn=2 12 15 67.8 4.2 - Mo=l 12 15 67.8 4.2 - Cr=l 12 lS
67.8 4.2 - Cr=l 12 15 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 69.2 3.8 - Mo=2 8 17 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 L7 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 17 67.5 4.5 3.0 - 8 17 70.9 4.1 - - 8 17 70.98 4.1 - - 8 17 69.9 4.1 - Mn=l 8 17 69.9 4.1 - Mn=l 8 17 69.0 4.0 - Mn=2 8 17 69.0 4.0 - Mn=2 8 17 68.0 4.0 - Mn=3 8 17 68.0 4.0 - Mn=3 8 17 67.1 3.9 - Mn=4 8 17 69.0 4.0 - Cr-2 8 17 69.0 4.0 - Cr=2 8 17 68.0 4.0 -Mn=2, Cr=l 8 17 ~68.0 4.0 -Mn=2, Cr=l 8 17 69.1 4.0 - Nb=2 8 17 68.1 4.0 1.4Mo=1.5 8 17 ,~
-~ -16- 1317~8~
Co Fe Ni M B Si 68.1 4.0 1.4Mo=1.5 8 17 65.7 4.4 2.7Mo~2 23 C=3*
65.7 4.4 2.9Mo~2 23 2 68.6 4.4 - Mo-2 21 Ge=4*
69.2 3.8 - Mo=2 10 15 69.0 3.0 - Mn=3 10 15 68.5 2.5 - Mn=4 10 15 68.8 4.2 - Cr=2 10 15 * All of Si content is replaced by the indicated element.
.
-- 1317~
T~(C) t~(min.) L(W/kg) 460 15 352,300 460 15** 392,000 460 15*** 143,400 430 120 142,800 420 15 6.76,000 480 15 4.614,000 500 15 4.4~,300 480 15 4.017,600 500 15 4.517,000 500 15 4.027,600 480 15 4.024,700 500 15 3.722,500 460 15 9.05,400 460 30 6.314,900 460 45 6.613,800 460 90 6.714,400 460 105 6.914,800 380 45 193,000 380 60 202,800 380 90 212,900 ~ 380 105 182,900 420 15 223,000 400 15 312,400 420 15 152,000 400 15 232,800 420 15 162,700 400 15 113,800 420 15 113,800 400 15 8.05,500 420 15 105,200 420 15 5.79,250 420 15 5.512,500 440 15 4.713,200 420 15 4.810,000 440 15 4.710,500 440 15 4.211,200 440 15 6.68,200 -18- 1 3 1 7 ~ ~ 'L~
Ta(C) t~(min.) L(W/kg)~ _ 460 15 7.27,100 440 15 20 2,000 450 15 27 2,800 480 15 9.75,200 450 60 9.19,600 460 60 10 7,700 440 15 8.3~,500 440 15 8.38,200 460 15 5.710,300 ** Cooling rate Y -3C/min.
*** Cooling rate ~ -60C/min.
EXAMPLES
1. Sample Preparation The glassy alloys listed in Tables I-III were rapidly quenched (about 106 K/sec) from the melt following the techniques taught by Chen and Polk in U.S
Patent 3,856,513. The resu]ting ribbons, typically 25 to 30 ~m thick and 0.5 to 2.5 cm wide, were determined to be free of significant crystallinity by X-ray diffractometry (using CuK radiation) and scanning calorimetry. Ribbons of the glassy metal alloys were strong, shiny, hard and ductile.
2 Magnetic Measurements .
Continuous ribbons of the glassy metal alloys prepared in accordance with the procedure described in Example I were wound onto bobbins (3.8 cm O.D.) to form closed-magnetic-path toroidal samples. Each sample contained from 1 to 3 9 of ribbon. Insulated primary and secondary windings (numbering at least 10 each) were applied to the toroids. These samples were used to obtain hysteresis loops (coercivity and remanence) and initial permeability with a commercial curve tracer and core loss (IEEE Standard 106-1972).
The saturation magnetization, Ms~ of each sample, was measured with a commercial vibrating sample . , -lg- 1~17~
magnetometer (Princeton Applied Research). In this case, the ribbon was cut into sevecal small squares (approximately 2 mm x 2 mm). These wer~ randomly oriented about their normal direction, their plane being parallel to the applied field (0 to 720 kA/m. The saturation induction Bs (=4 ~MSD) was then calculated by using the measured mass density D.
The ferromagnetic Curie temperature ( ~f) was measured by inductance method and also monitored by differential scanning calorimetry, which was used primarily to determine the crystallization temperatures.
Magnetostriction measurements employed metallic strain gauges (BLH Electronics), which were bonded (Eastman - 910 Cement) between two short lengths of ribbon. The ribbon axis and gauge axis were parallel.
The magnetostriction was determined as a function of applied field from the longitudinal s~rain in the parallel ( ~Q/ Q) ~ and perpendicular ( ~ Q/Q) 1 in-plain fields, according to the formula ~ = 2/3 ~(QQ/Q)~
- ( ~Q/Q) 1 ]
Having thus described the invention in rather full detail, it will be understood that this detail need not be strictly adhered to but that further changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the subjoined claims.
Claims (15)
1. A magnetic alloy that at least 70% glassy, having the formula CoaFebNicMdBcSif, where M is at least one member selected from the group consisting of Cr, Mo, Mn and Nb, "a" - "f" are in atom percent and the sum of "a" - "f" equals 100, "a" ranges from about 66 to about 71, "b" ranges from about 2.5 to about 4.5, "c" ranges from 0 to about 3, "d" ranges from 0 to about 2 except when M=Mn in which case "d" ranges from 0 to about 4, "e"
ranges from about 6 to about 24 and "f" ranges from 0 to about 19, with the proviso that the sum of "a", "b" and "c" ranges from about 72 to about 76 and the sum of "e"
and "f" ranges from about 25 to about 27, said alloy having a value of magnetostriction between -1x10-6 and +
1x10-6, a saturation induction ranging from about 0.5 to about 1 Tesla, a Curie temperature ranging from about 200 to about 450°C and a first crystallization temperature ranging from about 440 to about 570°C, said alloy having been heat-treated by heating the alloy to a temperature between about 50° to about 110°C below the first crystallization temperature for a time of from about 15 to about 180 minutes, and then cooling the alloy at a rate slower than about -60°C/min, said alloy further having bulk properties comprising a constricted hysteresis loop.
ranges from about 6 to about 24 and "f" ranges from 0 to about 19, with the proviso that the sum of "a", "b" and "c" ranges from about 72 to about 76 and the sum of "e"
and "f" ranges from about 25 to about 27, said alloy having a value of magnetostriction between -1x10-6 and +
1x10-6, a saturation induction ranging from about 0.5 to about 1 Tesla, a Curie temperature ranging from about 200 to about 450°C and a first crystallization temperature ranging from about 440 to about 570°C, said alloy having been heat-treated by heating the alloy to a temperature between about 50° to about 110°C below the first crystallization temperature for a time of from about 15 to about 180 minutes, and then cooling the alloy at a rate slower than about -60°C/min, said alloy further having bulk properties comprising a constricted hysteresis loop.
2. The magnetic alloy of claim 1 having the formula Co70.5Fe4.5B15Si10.
3. The magnetic alloy of claim 1 having the formula Co65.7Fe4.4Ni2.9MO2B11Si14.
4. The magnetic alloy of claim 1 having the formula Co68.2Fe3.8Mn1B12Si15.
5. The magnetic alloy of claim 1 having the formula Co67.8Fe4.2Mo1B12Si15.
6. The magnetic alloy of claim 1 having the formula Co67.8Fe4.2Cr1B12Si15.
7. The magnetic alloy of claim 1 having the formula Co69.2Fe3.8Mo2B8Si17.
8. The magnetic alloy of claim 1 having the formula Co67.5Fe4.5Ni3.0B8Si17.
9. The magnetic alloy of claim 1 having the formula Co70.9Fe4.5B8Si17.
10. The magnetic alloy of claim 1 having the formula Co69.9Fe4.1Mn1.0B8Si17.
11. The magnetic alloy of claim 1 having the formula Co69.0Fe4.0Mn2B8Si17.
12. The magnetic alloy of claim 1 having the formula Co68.0Fe4.0Mn3B8Si17.
13. The magnetic alloy of claim 1 having the formula Co69.0Fe4.0Cr2B8Si17.
14. The magnetic alloy of claim 1 having the formula Co68.0Fe4.0Mn2Cr1B8Si17.
15. The magnetic alloy of claim 1 having the formula Co69.0Fe4.0Nb2B8Si17.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US81719386A | 1986-01-08 | 1986-01-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1317484C true CA1317484C (en) | 1993-05-11 |
Family
ID=25222548
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000533379A Expired - Lifetime CA1317484C (en) | 1986-01-08 | 1987-03-31 | Glassy metal alloys with perminvar characteristics |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0240600B1 (en) |
| JP (2) | JP2552274B2 (en) |
| CA (1) | CA1317484C (en) |
| DE (1) | DE3685326D1 (en) |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5003291A (en) * | 1988-12-27 | 1991-03-26 | Strom Olsen John O | Ferromagnetic fibers having use in electronical article surveillance and method of making same |
| US5015992A (en) * | 1989-06-29 | 1991-05-14 | Pitney Bowes Inc. | Cobalt-niobium amorphous ferromagnetic alloys |
| US6457464B1 (en) | 1996-04-29 | 2002-10-01 | Honeywell International Inc. | High pulse rate spark ignition system |
| CN1220764A (en) * | 1996-04-29 | 1999-06-23 | 联合信号公司 | Magnetic core-coil assembly for spark ignition system |
| US5923236A (en) * | 1996-04-29 | 1999-07-13 | Alliedsignal Inc. | Magnetic core-coil assembly for spark ignition system |
| US5844462A (en) * | 1996-04-29 | 1998-12-01 | Alliedsignal Inc. | Magnetic core-coil assembly for spark ignition systems |
| AU730181B2 (en) | 1997-09-18 | 2001-03-01 | Allied-Signal Inc. | High pulse rate ignition source |
| JP4755340B2 (en) | 1998-09-17 | 2011-08-24 | ヴァキュームシュメルツェ ゲーエムベーハー ウント コンパニー カーゲー | Current transformer with DC current tolerance |
| JP2002530853A (en) * | 1998-11-13 | 2002-09-17 | バクームシユメルツエ、ゲゼルシヤフト、ミツト、ベシユレンクテル、ハフツング | Magnetic core suitable for use in current transformer, method of manufacturing the same, and current transformer |
| GB2374084A (en) * | 2001-04-03 | 2002-10-09 | Fourwinds Group Inc | Alloys having bistable magnetic behaviour |
| JP5700328B2 (en) * | 2010-04-26 | 2015-04-15 | セイコーエプソン株式会社 | Co-based metallic glass alloy, magnetic core, electromagnetic transducer and watch |
| ES2524733B2 (en) * | 2014-07-25 | 2015-03-31 | Universidad Complutense De Madrid | Wireless sensor to detect pressure |
| WO2018128149A1 (en) * | 2017-01-05 | 2018-07-12 | Tdk株式会社 | Core, and reactor, current limiter, electromagnetic actuator and motor using said core |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE7511398L (en) * | 1974-10-21 | 1976-04-22 | Western Electric Co | MAGNETIC DEVICE |
| US4188211A (en) * | 1977-02-18 | 1980-02-12 | Tdk Electronics Company, Limited | Thermally stable amorphous magnetic alloy |
| JPS5934780B2 (en) * | 1977-12-16 | 1984-08-24 | 松下電器産業株式会社 | Heat treatment method for amorphous magnetic alloy thin plate |
| JPS5825449A (en) * | 1981-08-05 | 1983-02-15 | Toshiba Corp | Amorphous magnetic alloy for magnetic head |
| DE3275492D1 (en) * | 1982-01-18 | 1987-04-02 | Allied Corp | Near-zero magnetostrictive glassy metal alloys with high magnetic and thermal stability |
| JPS59179751A (en) * | 1983-03-31 | 1984-10-12 | Toshiba Corp | Amorphous alloy for saturable reactor |
-
1986
- 1986-11-07 DE DE8686115434T patent/DE3685326D1/en not_active Expired - Lifetime
- 1986-11-07 EP EP19860115434 patent/EP0240600B1/en not_active Expired
-
1987
- 1987-01-08 JP JP62002562A patent/JP2552274B2/en not_active Expired - Lifetime
- 1987-03-31 CA CA000533379A patent/CA1317484C/en not_active Expired - Lifetime
-
1995
- 1995-10-11 JP JP7263164A patent/JP2907271B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0240600B1 (en) | 1992-05-13 |
| EP0240600A1 (en) | 1987-10-14 |
| JP2907271B2 (en) | 1999-06-21 |
| DE3685326D1 (en) | 1992-06-17 |
| JPH08188858A (en) | 1996-07-23 |
| JP2552274B2 (en) | 1996-11-06 |
| JPS62170446A (en) | 1987-07-27 |
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