CA2019617C - Cobalt-niobium amorphous ferromagnetic alloys - Google Patents
Cobalt-niobium amorphous ferromagnetic alloysInfo
- Publication number
- CA2019617C CA2019617C CA002019617A CA2019617A CA2019617C CA 2019617 C CA2019617 C CA 2019617C CA 002019617 A CA002019617 A CA 002019617A CA 2019617 A CA2019617 A CA 2019617A CA 2019617 C CA2019617 C CA 2019617C
- Authority
- CA
- Canada
- Prior art keywords
- marker
- amorphous
- ferromagnetic
- fiber
- niobium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2405—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used
- G08B13/2408—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting characterised by the tag technology used using ferromagnetic tags
- G08B13/2411—Tag deactivation
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C45/00—Amorphous alloys
- C22C45/04—Amorphous alloys with nickel or cobalt as the major constituent
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2428—Tag details
- G08B13/2437—Tag layered structure, processes for making layered tags
- G08B13/244—Tag manufacturing, e.g. continuous manufacturing processes
-
- G—PHYSICS
- G08—SIGNALLING
- G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
- G08B13/00—Burglar, theft or intruder alarms
- G08B13/22—Electrical actuation
- G08B13/24—Electrical actuation by interference with electromagnetic field distribution
- G08B13/2402—Electronic Article Surveillance [EAS], i.e. systems using tags for detecting removal of a tagged item from a secure area, e.g. tags for detecting shoplifting
- G08B13/2428—Tag details
- G08B13/2437—Tag layered structure, processes for making layered tags
- G08B13/2442—Tag materials and material properties thereof, e.g. magnetic material details
-
- 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
-
- 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
- H01F1/15391—Elongated structures, e.g. wires
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/9265—Special properties
- Y10S428/928—Magnetic property
Abstract
Amorphous ferromagnetic alloys having a niobium content in the range of 2.5 to 15 atomic percent have been conceived. These alloys are obtained directly in the amorphous state or as a mixture of amorphous and crystalline places. These alloys have superior properties relative to prior known amorphous and some amorphous alloys. The amorphous ferromagnetic alloys of this invention are .readily produced by rapid solidification techniques with no need for subsequent treatment.
Description
nt~ 'i r4~.1).e.~L~~~
r~O.L~Ah'1'-NIOF3IUM AMORPHOUS I'RRROM~IG3dETTC .llIaLOYS
RF.hA'.L'T;1) AI'PLICA'L'IONS
lt.te:ntion i.s di.xwr.t.c:d to co-pending patent applications luc:~v inc! sicni).ar subject matter entit:Led Electromagnetic Metal I~:i ko~t::~ IIaving Uwe lrt Floc:tronic Article Survuil7.ance Marlters Arc! P9ethod OF Making Same, Serial No. ;2,00.6"22I; and Filed l~c;c~rnrLte:t 2 0, i.g89 and Ferromagnetic Alloys With I-Iigh Nickel Content: And High I'~:rmc~abi7.ity Filed concurrently herewith.
1:3ACKG:ROUND OI~ TFIT; INVENTION
Amorphous l; errotnagnetic alloys axe vaell known and have had W .de use throughout a.ndustry. One area where amorphous fer.rornagnetic alloys are receiving particular attention is in tL~c~ field ol: elc~rt.x~onic .article surveillance (EAS) as disclosed by Picard :i.n French Pat. No. 763,681 (1931).
Generally, curtain amorphous :ferromagnetic alloys exhibit laic~V magnetic permeability and low coercivity thereby making the:Lr use as an EAS marker attractive. In the prior art, it was suggested !:o use aurromagnetic strips or wires sandwiched between two attacltud layers of dielectric rllatCrla.l. to form marltc:rs that can be detected in a magnetic f:i.e.ld as described in U. S. Pat. Nos. X1;581,524 and ~1,~~68,92:1, respectively. U. S. Pat. No. 3,856,5.3 describes various ;:amorphous furromac~ziet:ia alloys and methods for m~~~:ing the same. Ali~Mouglo prior amorphous ferromagnetic aJ.:loys lave worked well, it would be advantageous to have amo.rLahous ferromagnetic alloys that have properties that ~.e:nd ttrumselves to use irt an EAS marker and are easy to :1_abricate, w~xile being less expertsive The reason far the 30 relatively high cost of ~.rior amorphous ferromafnetic alloys leaving desired proper t:i.es was occasioned by the need to :irtclucle a high content o:E boron in their compositions;
usua:l..ly laetween 7 and 20% ~ororu i~ , an e~pensiVe rnaterial n r j B :~
acol ge:zaerally :is the most expensive ingredient in prior amo phous Ferromagnetic materials.
SUMMARY OF THE TNVEN'_CION
Novel compositions of amorphous ferromagnetic alloys have laden conceived having a high cobalt-niobium content with a reduced presence o:E boron in such alloys. These amorphous ferromagnetic alloys contain between approximately
r~O.L~Ah'1'-NIOF3IUM AMORPHOUS I'RRROM~IG3dETTC .llIaLOYS
RF.hA'.L'T;1) AI'PLICA'L'IONS
lt.te:ntion i.s di.xwr.t.c:d to co-pending patent applications luc:~v inc! sicni).ar subject matter entit:Led Electromagnetic Metal I~:i ko~t::~ IIaving Uwe lrt Floc:tronic Article Survuil7.ance Marlters Arc! P9ethod OF Making Same, Serial No. ;2,00.6"22I; and Filed l~c;c~rnrLte:t 2 0, i.g89 and Ferromagnetic Alloys With I-Iigh Nickel Content: And High I'~:rmc~abi7.ity Filed concurrently herewith.
1:3ACKG:ROUND OI~ TFIT; INVENTION
Amorphous l; errotnagnetic alloys axe vaell known and have had W .de use throughout a.ndustry. One area where amorphous fer.rornagnetic alloys are receiving particular attention is in tL~c~ field ol: elc~rt.x~onic .article surveillance (EAS) as disclosed by Picard :i.n French Pat. No. 763,681 (1931).
Generally, curtain amorphous :ferromagnetic alloys exhibit laic~V magnetic permeability and low coercivity thereby making the:Lr use as an EAS marker attractive. In the prior art, it was suggested !:o use aurromagnetic strips or wires sandwiched between two attacltud layers of dielectric rllatCrla.l. to form marltc:rs that can be detected in a magnetic f:i.e.ld as described in U. S. Pat. Nos. X1;581,524 and ~1,~~68,92:1, respectively. U. S. Pat. No. 3,856,5.3 describes various ;:amorphous furromac~ziet:ia alloys and methods for m~~~:ing the same. Ali~Mouglo prior amorphous ferromagnetic aJ.:loys lave worked well, it would be advantageous to have amo.rLahous ferromagnetic alloys that have properties that ~.e:nd ttrumselves to use irt an EAS marker and are easy to :1_abricate, w~xile being less expertsive The reason far the 30 relatively high cost of ~.rior amorphous ferromafnetic alloys leaving desired proper t:i.es was occasioned by the need to :irtclucle a high content o:E boron in their compositions;
usua:l..ly laetween 7 and 20% ~ororu i~ , an e~pensiVe rnaterial n r j B :~
acol ge:zaerally :is the most expensive ingredient in prior amo phous Ferromagnetic materials.
SUMMARY OF THE TNVEN'_CION
Novel compositions of amorphous ferromagnetic alloys have laden conceived having a high cobalt-niobium content with a reduced presence o:E boron in such alloys. These amorphous ferromagnetic alloys contain between approximately
2.5 and 15 atomic weight :percent niobium, 65 and '75n cobalt, leas than 15°-" baron and various percentages of iron and Sla.:iCOTl.
'L'he niobium containing amorphous ferromagnetic alloys oI the instant invention exhibit high magnetic permeability and low cocrcivity. :fn addition, these alloys have high eleca.rical res:istivity, are high corrosion .resistance, 15 akility to withstand degradation of,performance under repeated mechanical stressing and are simple to fabricate and reclui.re no treatment after manufacture and before ixzcar~?oration :into an EAS marker .
A primary advantage of the amorphous ferromagnetic 2o a1_7.~~Ys of the ~.nstant invention is that 'these alloys contain <~ppreriably less boron than prior amorphous ferromagnetic a:L.l.oys. Boron is an expexzsive component of prior amorphous ferromagnetic alloys and its percentage reduction is for this reason beneficial.
DESCRIPTTON OF THE DRAWING
:Fig. 1 is a langi.tudinal crass sectional view of a melt extraction device fox pr.oduci.ng amorphous ferromagnetic alloys in accordance with the instant invention;
Hig. ?. is azz enlarged, crass sectional view taken slang 3o the lines 2-2. of Fig. 1 and show.i:ng details of tile perimeter of the spinning disk spawn a.n Fig. ~1;
I'ig. 3 is a cxass sectional view takan along the lines
'L'he niobium containing amorphous ferromagnetic alloys oI the instant invention exhibit high magnetic permeability and low cocrcivity. :fn addition, these alloys have high eleca.rical res:istivity, are high corrosion .resistance, 15 akility to withstand degradation of,performance under repeated mechanical stressing and are simple to fabricate and reclui.re no treatment after manufacture and before ixzcar~?oration :into an EAS marker .
A primary advantage of the amorphous ferromagnetic 2o a1_7.~~Ys of the ~.nstant invention is that 'these alloys contain <~ppreriably less boron than prior amorphous ferromagnetic a:L.l.oys. Boron is an expexzsive component of prior amorphous ferromagnetic alloys and its percentage reduction is for this reason beneficial.
DESCRIPTTON OF THE DRAWING
:Fig. 1 is a langi.tudinal crass sectional view of a melt extraction device fox pr.oduci.ng amorphous ferromagnetic alloys in accordance with the instant invention;
Hig. ?. is azz enlarged, crass sectional view taken slang 3o the lines 2-2. of Fig. 1 and show.i:ng details of tile perimeter of the spinning disk spawn a.n Fig. ~1;
I'ig. 3 is a cxass sectional view takan along the lines
3-3 of Fig. 1 showing the cross section a fiber produced by the device of Fig. 1;
_ ~ _ G j lv ~ I'~ .1 ~cI ~.I .i~ eJr 'L'4 .f~
Fig. .4 is a plan view of a composite web including fibers made by the device shown in Fig. 2;
I'ig. 5 is a cross sectional view taken along the lines 5-5 of. Fig. 4 showing a side elevational view of the composite web; a.nd Fig. 6 is a plan view of a label including a strip of amorphous ferromagnetic alloy within a label.
Fig. 7 is a plot showing contours of equal differential magnetic permeability as a function of the composition of to amorphous ferromagnetic alloys.
~i ~',1 ~ 1 ~, ~a.
J .li. rJ
DETAITrED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reducing the content of boran in an amorphous ferromagnetic alloy leads to the advantage of lower cost.
Allays have been found which exhibit high magnetic permeability although having reduced quantities of boron in their composition. These amorphous ferromagnetic alloys have the following general formula:
Coa Feb Nbc Sid Be where 100 > a + b -H c + d + a > 99% and whose lp individual values lie in the fallawing ranges:
a = 65% to 79%
b = 2 to 7%
c = 2.5% to 15%
d ~ less than 24% inclusive a = less than 12% inclusive and and 0 < d + a < 14 when 0 <_ d _< 4 0<e<10 when4<_d<_ 5 0<_e<_l0ar when5__<d<_ 7 a _<. 7.2 and d -H a <_ 17 when 5 <_ d <_ 7 p < a < 12 when 7 _< d <_ 8 0_<d+e< 20 when8<_d<_ 12 0 __<.e<_8 when l2<_d<_15 0 S d + a 5 2 3 whexz 15 < d S 18 0 5 a < 5 when 18 <_ d <_ 20 All o.f the above percentages are in atomic percent as well as throughout the balance of this specification including the claims.
solidification at cooling rates of t~etween 1 and 2 x 1.OOKs 1. The alloys are amorphous or a mixture of amorphous and less than 50°-" crystalline phases.
Specific examples of amorphous ferromagnetic alloys are given in the following table:
TABhE II
Co Fe Nb Si B ~ Amorphous :~ 71 4 2.5 16 ~.5 >70 TI 71.5 4 3.5 16,5 4.5 >70 io III 71 ~~ 4 16 5 >70 IV 71 4 9 1~ 2. >70 V 71 ~ ~ 13 3 >70 TYae percent of material in the amorphous phase has been estimated from X-ray diffractiorx measurement and enthalpy of 1S crystallization.
The advantages of this niobium-cobalt amorphous ferromagnetic alloys over prior alloys are:
~3 1~ ~ c~ f.~ ~. rA
(1) Enhanced magnetic performance: at 6kfIz the differential magnetic permeability at the coercive field for some if the cobalt-niobium amorphous .ferromagnetic alloys of the instant invention is up to 50% greater than prior amorphous :Ferromagnetic alloys.
(2) Low boron concentration: the boron content is below the level of prior amorphous and partially amorphous ferromagnetic alloys, the boron content 0 of the instant allay being as low as 2%. Boron is the most expensive component of prior amorphous ferromagnetic alloys and its percentage reduction is obviously beneficial. It is believed that the reduction of 'the boron content and the inclusion of niobium, a micxostructure with small crystallites in the amorphous matrix is formed that results in enhanced magnetic properties.
In other characteristics, the instant amorphous ferromagnetic alloys are at least equal to prior 2o amorphous ferromagnetic alloys.
Fig. 7 displays the permeability in a magnetic field of 6kHz of the alloy series Go~lFe4Nb25r~_ySi~By, the shaded portion representing the range of composition of prior alloys. The numbers associated with the curved lines represent the vahze of permeability with the highest permeab~.lity sh°wn dotted, i.e. 180,000:
When prepared Y~y rapid solidification, cooling rate greater than 5 x lUS °K s f, the matexial can be used in any of the following formse ribbons, foil,',flakes, 30 wires and fibers: 'A major advantage of the alloys of ~~.r'_rlr.J_~r~
the instant invention can be used in EAS application as east.
A1.1 alloy compositions included in the above tables can be fabricated by the rapid solidification process (melt extraction) in the form of fuze fibers i.e., a diameter of less than 80 ~.un. The amorphous, as well as partially amorphous samples of the alloys were all ductile in the as quenched condition.
The density of the instant alloys was found to be about 8 io g/cm~ .
Referring initially to Figs. 1-3, a rotating-wheel device capable of producing rapid solidification is shown generally at 10 that produces amorphous ferromagnetic fibers in accordance with the principles of the instant invention.
What is shown and will be described is a melt extraction technique, but it will be appreciated that other techniques can be used in practicing the invention including melt spinning, melt drag and pendent drop method. Additionally, the fibers and ribbon of the instant invention can be molded 2o in plastics, rubber and resins and can be cast in low temperature metal molds without detexiorating the magnetic properties.
The spinning device l0 includes a disk 12, or wheel, which is fixedly supported by a rotatable shaft l3 which is z~ mounted on a movable arm l9. The disk 7.2 has a reduced section 19 at its perimeter which has an edge 16 that can vary in thickness depending upon whether fiber or ribbon is to be spun. The disk l2 used in the reduction to practice of the invention had a d~.ameter of six inches and the edge so 16 had a radius of curvature of approximately 30 microns, but 5 to 50 microns would be acceptable for the produa~ion of fibers. Where ribbon is to be spun, the edge 76 would be:
thickened substantially depending an.the width of ribbon to be produced. The shaft l3 is in engagement wiah a motor l7 .. 7 -~~; ~J ~~ ~ i by any cozzvenient means so that the shaft, and the disk 12 that is mounted thereon, can be rotated.
A cup shaped tundish J.8 is disposed below the disk 12 and is adapted to receive a metal alloy composition 20.
Tnduction coils 22 are disposed around the tundish 18 and are connected to a source of power 23. Upon sufficient power being applied to the coils 22, the metal alloy composition 20 within the tundish 18 will become molten.
The disk 12 is rotated as indicated by the arrow in Fig. 1 1o arzd upon the disk rotating within the molten alloy composition, it will praduce a fiber 24 which can be cut to any desired length. optionally, in contact with the flange 14 is a wiper 26 made of a material such as cloth far the purpose of keeping the reduced section 14 clean.
Referring now to Figs. 4 and 5, the fibers 24 are aligned relative to one another and located between upper and lower sheets 30,32 respectfully, that are joined by an adhesive 34 to form a markex which is shown in the form of a label 28. The labels 28 are supparted by a web 36 and can 2o be applied to the surface of an article through use of a labeller as is known in the art. As used in this disclosure, the term label is intended to include tickets arid tags as well. Reference can be had to U. S. Pat. No.
_ ~ _ G j lv ~ I'~ .1 ~cI ~.I .i~ eJr 'L'4 .f~
Fig. .4 is a plan view of a composite web including fibers made by the device shown in Fig. 2;
I'ig. 5 is a cross sectional view taken along the lines 5-5 of. Fig. 4 showing a side elevational view of the composite web; a.nd Fig. 6 is a plan view of a label including a strip of amorphous ferromagnetic alloy within a label.
Fig. 7 is a plot showing contours of equal differential magnetic permeability as a function of the composition of to amorphous ferromagnetic alloys.
~i ~',1 ~ 1 ~, ~a.
J .li. rJ
DETAITrED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reducing the content of boran in an amorphous ferromagnetic alloy leads to the advantage of lower cost.
Allays have been found which exhibit high magnetic permeability although having reduced quantities of boron in their composition. These amorphous ferromagnetic alloys have the following general formula:
Coa Feb Nbc Sid Be where 100 > a + b -H c + d + a > 99% and whose lp individual values lie in the fallawing ranges:
a = 65% to 79%
b = 2 to 7%
c = 2.5% to 15%
d ~ less than 24% inclusive a = less than 12% inclusive and and 0 < d + a < 14 when 0 <_ d _< 4 0<e<10 when4<_d<_ 5 0<_e<_l0ar when5__<d<_ 7 a _<. 7.2 and d -H a <_ 17 when 5 <_ d <_ 7 p < a < 12 when 7 _< d <_ 8 0_<d+e< 20 when8<_d<_ 12 0 __<.e<_8 when l2<_d<_15 0 S d + a 5 2 3 whexz 15 < d S 18 0 5 a < 5 when 18 <_ d <_ 20 All o.f the above percentages are in atomic percent as well as throughout the balance of this specification including the claims.
solidification at cooling rates of t~etween 1 and 2 x 1.OOKs 1. The alloys are amorphous or a mixture of amorphous and less than 50°-" crystalline phases.
Specific examples of amorphous ferromagnetic alloys are given in the following table:
TABhE II
Co Fe Nb Si B ~ Amorphous :~ 71 4 2.5 16 ~.5 >70 TI 71.5 4 3.5 16,5 4.5 >70 io III 71 ~~ 4 16 5 >70 IV 71 4 9 1~ 2. >70 V 71 ~ ~ 13 3 >70 TYae percent of material in the amorphous phase has been estimated from X-ray diffractiorx measurement and enthalpy of 1S crystallization.
The advantages of this niobium-cobalt amorphous ferromagnetic alloys over prior alloys are:
~3 1~ ~ c~ f.~ ~. rA
(1) Enhanced magnetic performance: at 6kfIz the differential magnetic permeability at the coercive field for some if the cobalt-niobium amorphous .ferromagnetic alloys of the instant invention is up to 50% greater than prior amorphous :Ferromagnetic alloys.
(2) Low boron concentration: the boron content is below the level of prior amorphous and partially amorphous ferromagnetic alloys, the boron content 0 of the instant allay being as low as 2%. Boron is the most expensive component of prior amorphous ferromagnetic alloys and its percentage reduction is obviously beneficial. It is believed that the reduction of 'the boron content and the inclusion of niobium, a micxostructure with small crystallites in the amorphous matrix is formed that results in enhanced magnetic properties.
In other characteristics, the instant amorphous ferromagnetic alloys are at least equal to prior 2o amorphous ferromagnetic alloys.
Fig. 7 displays the permeability in a magnetic field of 6kHz of the alloy series Go~lFe4Nb25r~_ySi~By, the shaded portion representing the range of composition of prior alloys. The numbers associated with the curved lines represent the vahze of permeability with the highest permeab~.lity sh°wn dotted, i.e. 180,000:
When prepared Y~y rapid solidification, cooling rate greater than 5 x lUS °K s f, the matexial can be used in any of the following formse ribbons, foil,',flakes, 30 wires and fibers: 'A major advantage of the alloys of ~~.r'_rlr.J_~r~
the instant invention can be used in EAS application as east.
A1.1 alloy compositions included in the above tables can be fabricated by the rapid solidification process (melt extraction) in the form of fuze fibers i.e., a diameter of less than 80 ~.un. The amorphous, as well as partially amorphous samples of the alloys were all ductile in the as quenched condition.
The density of the instant alloys was found to be about 8 io g/cm~ .
Referring initially to Figs. 1-3, a rotating-wheel device capable of producing rapid solidification is shown generally at 10 that produces amorphous ferromagnetic fibers in accordance with the principles of the instant invention.
What is shown and will be described is a melt extraction technique, but it will be appreciated that other techniques can be used in practicing the invention including melt spinning, melt drag and pendent drop method. Additionally, the fibers and ribbon of the instant invention can be molded 2o in plastics, rubber and resins and can be cast in low temperature metal molds without detexiorating the magnetic properties.
The spinning device l0 includes a disk 12, or wheel, which is fixedly supported by a rotatable shaft l3 which is z~ mounted on a movable arm l9. The disk 7.2 has a reduced section 19 at its perimeter which has an edge 16 that can vary in thickness depending upon whether fiber or ribbon is to be spun. The disk l2 used in the reduction to practice of the invention had a d~.ameter of six inches and the edge so 16 had a radius of curvature of approximately 30 microns, but 5 to 50 microns would be acceptable for the produa~ion of fibers. Where ribbon is to be spun, the edge 76 would be:
thickened substantially depending an.the width of ribbon to be produced. The shaft l3 is in engagement wiah a motor l7 .. 7 -~~; ~J ~~ ~ i by any cozzvenient means so that the shaft, and the disk 12 that is mounted thereon, can be rotated.
A cup shaped tundish J.8 is disposed below the disk 12 and is adapted to receive a metal alloy composition 20.
Tnduction coils 22 are disposed around the tundish 18 and are connected to a source of power 23. Upon sufficient power being applied to the coils 22, the metal alloy composition 20 within the tundish 18 will become molten.
The disk 12 is rotated as indicated by the arrow in Fig. 1 1o arzd upon the disk rotating within the molten alloy composition, it will praduce a fiber 24 which can be cut to any desired length. optionally, in contact with the flange 14 is a wiper 26 made of a material such as cloth far the purpose of keeping the reduced section 14 clean.
Referring now to Figs. 4 and 5, the fibers 24 are aligned relative to one another and located between upper and lower sheets 30,32 respectfully, that are joined by an adhesive 34 to form a markex which is shown in the form of a label 28. The labels 28 are supparted by a web 36 and can 2o be applied to the surface of an article through use of a labeller as is known in the art. As used in this disclosure, the term label is intended to include tickets arid tags as well. Reference can be had to U. S. Pat. No.
4,207,131 for details of a carrier web described herein.
z5 Preferably, the marker 28 has a length of less than one inch and preferably about 5/8". With such a size, the composite web 38 can be used in a commercial labeler such as an 1110 labeler available fxom Monarch Marking Systems Inc., Dayton, Ohio. Although the marker 28 is shown with upper and lower 3o sheets, 30,32, it will be appreciated that the fibers 24 can be adhered to the lower sheet 32 only and the upper sheet can be eliminated.
The source of power 23 is enabled so aswto cause the induction coils to heat the ferromagnetic alloy 20 above its 3s melting point thereby creating a molten bath of ferromagnetic alloy. As will. be noted, the reduced section _ g ..
c; r3 .,~ ., ~~ .t a:~ i~ .ti. r:7 &.i .l.
14 of the disk 12 extends into the metal. 20. Although the metal is shown having a dome appearance thereon, this is slightly exaggerated .f.or purposes of showing the reduced section 14 being received within the melt. In any case, a portion of the diameter of the disk 12 will extend below the upper most portions of the tundish to engage the ferromagnetic alloy 20 after. it has reached its melting temperature. Depending upon the temperature of the alloy, the arm 19 will be lowered so as to place the reduced zo section 14 within the metal alloy and the motor 17 will be enabled thereby rotating the disk 12. The disk 12 will be rotated in the direction as shown by the arrow in Fig. 1 and a .fiber of ferromagnetic metal 24 will be formed thereby.
This fiber 24 can be as long as is required.
15 :Ct will be appreciated that the rapid solidification process described will produce a fiber or ribbon that is in :ready to use condition i.e., it goes Pram 'the molten state directly to the solid state in a state for immediate use.
No subsequent treatment is required to achieve the 20 properties sought.
Under optirnum conditions, the fiber 24 could be of indefinite length, but it has been found that certain conditions affect the length of the fiber. The conditions that cause variation in the length of the fiber are 25 rotational velocity of the disk 12, vibrations in the system and shape and design of the disk and temperature of the melt.
The fiber 24 was cut into lengths of approximately 3/4 o:E an inch and planed upon a first layer 32 of a label. A
3o second layer 30 was placed over the fiber 24, in registration with the first layer, and wii:h adhesive therebetween sows to form a label 28: The fibers 24 may be placed in aligned spaced relationship, as shown in Fig. 4, approximately one mm apart, or thex can b~ located within 35 the label 28 in random fashion: :Ct has been foixnd that 3 ar.
more fibers placed in alignment would be suffi:ci~nt for the ~~3~~~ ~~
marker to be sensed in an interrogation zone; whereas, when the fibers when placed in random fashion, 5 or more fibers were sufficient. Placing the fibers 24 in random fashion, OVE:rlapplTlg one another is unique in 'the field. Previous markers required multiple elements be aligned with and/or sequential from one another. Other orientations are possible. One or more fibers coiled, bent or curved can also provide acceptable responses for detection. It was found that the minimum total weight of fibers 24 that are 1o detectable was approximately 0.2 milligrams. As shown in Fig. 6, an amorphous ferromagnetic ribbon 25 containing niobium as described herein can be used in a marker but the length of the .ribbon would be greater than the length of a fiber to be detectable.
1s :Ln the determination of the performance of an amorphous ferromagnetic marker, perhaps the most critical parameter is the t1/2 which is the measure of how sharp the pulse induced by such marker is in an interrogation zone. More specifically, t1/2 represents in microseconds the time lapse 2o between rising and trailing portions at one half the peak value of the induced signal. A value of t1/2 = 10 micro seconds or less is considered acceptable. A lower value is desirable because this indicates a sharp, easy to detect peak and hence high harmonic content.
The values of t 1/2 for various niobium-cobalt amorphous ferromagnetic alloy compositions are given in the table below:
~r ~ .~ ~~ i~ .5. ~~
m~BZ~~ z z z Co ke Nb Si ~i tl~~ at 6kHz tl~2at 10 kHz (u sec) (u sec) 71 ~ 5 13.5 6.5 3.5 3.3 71 4 7 10 8 6.0 -71 ~ 4.5 14 6.5 ~
Data taken with a full-scale sweep of 2 Oe field, sample mass between 0.33 mg to l.O mg and a length of 6 io cm .
z5 Preferably, the marker 28 has a length of less than one inch and preferably about 5/8". With such a size, the composite web 38 can be used in a commercial labeler such as an 1110 labeler available fxom Monarch Marking Systems Inc., Dayton, Ohio. Although the marker 28 is shown with upper and lower 3o sheets, 30,32, it will be appreciated that the fibers 24 can be adhered to the lower sheet 32 only and the upper sheet can be eliminated.
The source of power 23 is enabled so aswto cause the induction coils to heat the ferromagnetic alloy 20 above its 3s melting point thereby creating a molten bath of ferromagnetic alloy. As will. be noted, the reduced section _ g ..
c; r3 .,~ ., ~~ .t a:~ i~ .ti. r:7 &.i .l.
14 of the disk 12 extends into the metal. 20. Although the metal is shown having a dome appearance thereon, this is slightly exaggerated .f.or purposes of showing the reduced section 14 being received within the melt. In any case, a portion of the diameter of the disk 12 will extend below the upper most portions of the tundish to engage the ferromagnetic alloy 20 after. it has reached its melting temperature. Depending upon the temperature of the alloy, the arm 19 will be lowered so as to place the reduced zo section 14 within the metal alloy and the motor 17 will be enabled thereby rotating the disk 12. The disk 12 will be rotated in the direction as shown by the arrow in Fig. 1 and a .fiber of ferromagnetic metal 24 will be formed thereby.
This fiber 24 can be as long as is required.
15 :Ct will be appreciated that the rapid solidification process described will produce a fiber or ribbon that is in :ready to use condition i.e., it goes Pram 'the molten state directly to the solid state in a state for immediate use.
No subsequent treatment is required to achieve the 20 properties sought.
Under optirnum conditions, the fiber 24 could be of indefinite length, but it has been found that certain conditions affect the length of the fiber. The conditions that cause variation in the length of the fiber are 25 rotational velocity of the disk 12, vibrations in the system and shape and design of the disk and temperature of the melt.
The fiber 24 was cut into lengths of approximately 3/4 o:E an inch and planed upon a first layer 32 of a label. A
3o second layer 30 was placed over the fiber 24, in registration with the first layer, and wii:h adhesive therebetween sows to form a label 28: The fibers 24 may be placed in aligned spaced relationship, as shown in Fig. 4, approximately one mm apart, or thex can b~ located within 35 the label 28 in random fashion: :Ct has been foixnd that 3 ar.
more fibers placed in alignment would be suffi:ci~nt for the ~~3~~~ ~~
marker to be sensed in an interrogation zone; whereas, when the fibers when placed in random fashion, 5 or more fibers were sufficient. Placing the fibers 24 in random fashion, OVE:rlapplTlg one another is unique in 'the field. Previous markers required multiple elements be aligned with and/or sequential from one another. Other orientations are possible. One or more fibers coiled, bent or curved can also provide acceptable responses for detection. It was found that the minimum total weight of fibers 24 that are 1o detectable was approximately 0.2 milligrams. As shown in Fig. 6, an amorphous ferromagnetic ribbon 25 containing niobium as described herein can be used in a marker but the length of the .ribbon would be greater than the length of a fiber to be detectable.
1s :Ln the determination of the performance of an amorphous ferromagnetic marker, perhaps the most critical parameter is the t1/2 which is the measure of how sharp the pulse induced by such marker is in an interrogation zone. More specifically, t1/2 represents in microseconds the time lapse 2o between rising and trailing portions at one half the peak value of the induced signal. A value of t1/2 = 10 micro seconds or less is considered acceptable. A lower value is desirable because this indicates a sharp, easy to detect peak and hence high harmonic content.
The values of t 1/2 for various niobium-cobalt amorphous ferromagnetic alloy compositions are given in the table below:
~r ~ .~ ~~ i~ .5. ~~
m~BZ~~ z z z Co ke Nb Si ~i tl~~ at 6kHz tl~2at 10 kHz (u sec) (u sec) 71 ~ 5 13.5 6.5 3.5 3.3 71 4 7 10 8 6.0 -71 ~ 4.5 14 6.5 ~
Data taken with a full-scale sweep of 2 Oe field, sample mass between 0.33 mg to l.O mg and a length of 6 io cm .
Claims (25)
1. An amorphous ferromagnetic alloy having a composition comprising:
Co a Fe b Nb c Si d B e "a" ranges from 65 to 79%
"b" ranges from 2 to 7%
"c" ranges from 2.5 to 15%;
"d" is less than 16% inclusive "e" is less than 12% inclusive and wherein said ranges are in atomic percent.
Co a Fe b Nb c Si d B e "a" ranges from 65 to 79%
"b" ranges from 2 to 7%
"c" ranges from 2.5 to 15%;
"d" is less than 16% inclusive "e" is less than 12% inclusive and wherein said ranges are in atomic percent.
2. The amorphous ferromagnetic alloy of claim 1 and 0 ~ d + e ~ 14 when 0 ~ d ~ 4 0 ~ e ~ 10 when 4 ~ d ~ 5 0 ~ e ~ 10 when 5 ~ d ~ 7 e ~ 12 and d + e ~ 17 when 5 ~ d ~ 7 0 ~ e ~ 12 when 7 ~ d ~ 8 0 ~ d + e ~ 20 when 8 ~ d ~ 12 0 ~ e ~ 8 when 12 ~ d ~ 15 0 ~ d + e ~ 23 when 15 ~ d ~ 18 0 ~ e ~ 5 when 18 ~ d ~ 20
3. An amorphous ferromagnetic alloy containing 2.5 to 15% niobium and less than 12% boron and made by rapid solidification.
4. A marker for use in an electronic article surveillance system, the marker comprising: a marker element for producing a detectable response and including an amorphous ferromagnetic element made from a molten alloy containing 2.5 to 15% niobium, and a carrier for the marker element.
5. The marker of claim 4 wherein said amorphous ferromagnetic marker is a fiber.
6. The marker of claim 4 wherein said amorphous ferromagnetic marker is a ribbon.
7. The marker as defined in claim 4 wherein said .ferromagnetic fiber is produced from said molten alloy by rapid solidification. techniques.
8. A marker for use in an electronic article surveillance system, the marker comprising: an amorphous ferromagnetic element having 2.5 to 15% niobium, a length less than 15 millimeters and cross-sectional area of less than 6x10- 3 square millimeters.
9. The marker of claim 8 wherein said amorphous ferromagnetic element is a fiber.
10. The marker of claim 8 wherein said amorphous ferromagnetic element is a ribbon.
11. A marker as defined in claim 8, wherein the marker element has a t1/2 value of less than 10 microseconds at 6kHz.
12. A web of markers for use in an electronic article surveillance system, the web comprising: a web of labels and a plurality of amorphous, ferromagnetic marker elements having a composition containing 2.5 to 15% niobium and supported by each of the labels for producing a detectable response.
13, A method of making a marker for use in an electronic article surveillance system, comprising the steps of: rapidly solidifying an amorphous, ferromagnetic element having a composition containing 2.5 to 15% niobium from a pool of molten alloy, and incorporating the resulting element within a support.
14. The method as defined in claim 13, wherein the incorporating step includes incorporating the element into fabric.
15. The method as defined in claim 13, wherein the incorporating step includes adding the element into a pager-making slurry, and converting the slurry into paper.
16. The method as defined in claim 13, further comprising the step of cutting the element into a plurality of pieces, and wherein the incorporating step includes mounting the pieces on a plurality of support members.
17. The method as defined in claim 16, wherein the cutting step includes cutting the element into a plurality of. fiber pieces each having a predetermined length.
18. A method of making a web of markers for use in an electronic article surveillance system, comprising the steps of: providing a web of material, orienting amorphous, ferromagnetic elements having a composition containing 2.5 to 15% niobium on the web, and wherein the material is divided into labels each having at least one marker element.
19. A marker for producing a detectable response in an electronic article surveillance system, the marker comprising: a support element, an amorphous, ferromagnetic fiber having a composition containing 2.5 to 15% niobium supported by the support element, the fiber having a cross sectional area of less than 6x10 -3 square millimeters.
2). A ferromagnetic marker for use in an article surveillance system comprising:
an amorphous ferromagnetic fiber having a composition containing 2.5 to 7.5% niobium and an aspect ratio of greater than 150, said amorphous ferromagnetic fiber being positioned between two dielectric sheets, and said sheets begin joined so as to hold said amorphous ferromagnetic fibers therebetween to form a marker.
an amorphous ferromagnetic fiber having a composition containing 2.5 to 7.5% niobium and an aspect ratio of greater than 150, said amorphous ferromagnetic fiber being positioned between two dielectric sheets, and said sheets begin joined so as to hold said amorphous ferromagnetic fibers therebetween to form a marker.
21. The ferromagnetic marker of claim 20 wherein said marker has a length of less than one inch.
22. An amorphous, ferromagnetic fiber having a composition containing 2.5 to 15% niobium, a nominal diameter of less than 80 microns and a t1/2 of less than 10 microseconds in a driving frequency of 6kH Z and an amplitude in the order of one Oersted.
23. The fiber of claim 22 wherein said fiber has an aspect ratio greater than 150.
24. The fiber of claim 23 wherein said fiber has a kidney shaped cross section.
25. The fiber of claim 23 wherein said fiber has a generally circular cross section.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US07/372,991 US5015992A (en) | 1989-06-29 | 1989-06-29 | Cobalt-niobium amorphous ferromagnetic alloys |
| US372,991 | 1989-06-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2019617A1 CA2019617A1 (en) | 1990-12-29 |
| CA2019617C true CA2019617C (en) | 2001-01-30 |
Family
ID=23470479
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002019617A Expired - Fee Related CA2019617C (en) | 1989-06-29 | 1990-06-22 | Cobalt-niobium amorphous ferromagnetic alloys |
Country Status (3)
| Country | Link |
|---|---|
| US (1) | US5015992A (en) |
| CA (1) | CA2019617C (en) |
| GB (2) | GB2233346B (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3037821B2 (en) * | 1992-04-10 | 2000-05-08 | 日本フエルト株式会社 | Magnetic object to be detected |
| US5456718A (en) * | 1992-11-17 | 1995-10-10 | Szymaitis; Dennis W. | Apparatus for detecting surgical objects within the human body |
| US5664582A (en) * | 1992-11-17 | 1997-09-09 | Szymaitis; Dennis W. | Method for detecting, distinguishing and counting objects |
| US5605870A (en) * | 1993-05-28 | 1997-02-25 | Martinex Science, Inc. | Ceramic fibers, and methods, machines and compositions of matter for making same |
| DE9412456U1 (en) * | 1994-08-02 | 1994-10-27 | Vacuumschmelze Gmbh | Amorphous alloy with high magnetostriction and at the same time high induced anisotropy |
| DE69529890D1 (en) | 1995-06-05 | 2003-04-17 | Dennis W Szymaitis | Marked surgical item for electromagnetic perception |
| SE506167C2 (en) * | 1996-02-12 | 1997-11-17 | Rso Corp | Sensor for contactless detection of objects |
| CN110387511B (en) * | 2019-08-21 | 2021-06-29 | 合肥工业大学 | Co-Ni-Nb-B amorphous alloy strip and preparation method thereof |
Family Cites Families (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4257830A (en) * | 1977-12-30 | 1981-03-24 | Noboru Tsuya | Method of manufacturing a thin ribbon of magnetic material |
| US4365994A (en) * | 1979-03-23 | 1982-12-28 | Allied Corporation | Complex boride particle containing alloys |
| USRE32428E (en) * | 1979-04-23 | 1987-05-26 | Allied Corporation | Amorphous antipilferage marker |
| JPS5933183B2 (en) * | 1980-06-24 | 1984-08-14 | 株式会社東芝 | Low loss amorphous alloy |
| JPS5779052A (en) * | 1980-10-16 | 1982-05-18 | Takeshi Masumoto | Production of amorphous metallic filament |
| JPS5831053A (en) * | 1981-08-18 | 1983-02-23 | Toshiba Corp | Amorphous alloy |
| US4462826A (en) * | 1981-09-11 | 1984-07-31 | Tokyo Shibaura Denki Kabushiki Kaisha | Low-loss amorphous alloy |
| US4553136A (en) * | 1983-02-04 | 1985-11-12 | Allied Corporation | Amorphous antipilferage marker |
| JPS6183930A (en) * | 1984-09-29 | 1986-04-28 | Toshiba Corp | Pressure-differential pressure transmitter |
| US4745401A (en) * | 1985-09-09 | 1988-05-17 | Minnesota Mining And Manufacturing Company | RF reactivatable marker for electronic article surveillance system |
| JPS6288109A (en) * | 1985-10-14 | 1987-04-22 | Hitachi Ltd | Amorphous magnetic alloy magnetic head and its manufacture |
| DE3545647A1 (en) * | 1985-12-21 | 1987-06-25 | Vacuumschmelze Gmbh | DEACTIVATE SECURITY LABEL FOR ANTI-THEFT SECURITY SYSTEMS |
| DE3685326D1 (en) * | 1986-01-08 | 1992-06-17 | Allied Signal Inc | GLASS-LIKE ALLOYS WITH PERMINVAR PROPERTIES. |
| US4859256A (en) * | 1986-02-24 | 1989-08-22 | Kabushiki Kaisha Toshiba | High permeability amorphous magnetic material |
| US4823113A (en) * | 1986-02-27 | 1989-04-18 | Allied-Signal Inc. | Glassy alloy identification marker |
| US4710754A (en) * | 1986-09-19 | 1987-12-01 | Minnesota Mining And Manufacturing Company | Magnetic marker having switching section for use in electronic article surveillance systems |
| DE3775778D1 (en) * | 1986-11-03 | 1992-02-13 | Allied Signal Inc | METAL GLASS ALLOYS WITH VERY SMALL MAGNETOSTRICTION FOR HIGH FREQUENCY APPLICATIONS. |
| DE3717043A1 (en) * | 1987-05-21 | 1988-12-15 | Vacuumschmelze Gmbh | AMORPHOUS ALLOY FOR STRIP-SHAPED SENSOR ELEMENTS |
-
1989
- 1989-06-29 US US07/372,991 patent/US5015992A/en not_active Expired - Fee Related
-
1990
- 1990-06-22 CA CA002019617A patent/CA2019617C/en not_active Expired - Fee Related
- 1990-06-28 GB GB9014421A patent/GB2233346B/en not_active Expired - Fee Related
-
1993
- 1993-05-12 GB GB9309821A patent/GB2264716B/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| GB2233346B (en) | 1993-12-22 |
| GB2233346A (en) | 1991-01-09 |
| GB9014421D0 (en) | 1990-08-22 |
| GB2264716A (en) | 1993-09-08 |
| GB9309821D0 (en) | 1993-06-23 |
| CA2019617A1 (en) | 1990-12-29 |
| US5015992A (en) | 1991-05-14 |
| GB2264716B (en) | 1994-02-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5015993A (en) | Ferromagnetic alloys with high nickel content and high permeability | |
| US5003291A (en) | Ferromagnetic fibers having use in electronical article surveillance and method of making same | |
| EP0295028B1 (en) | Magnetic devices | |
| EP0833351A1 (en) | Fe group-based amorphous alloy ribbon and magnetic marker | |
| AU663773B2 (en) | Deactivatable/reactivatable magnetic marker having a step change in magnetic flux | |
| CA2019617C (en) | Cobalt-niobium amorphous ferromagnetic alloys | |
| EP1216465B1 (en) | A glass-coated amorphous magnetic microwire marker for article surveillance | |
| CA1238384A (en) | Theft detection apparatus and target and method of making same | |
| US6747559B2 (en) | Glass-coated amorphous magnetic mircowire marker for article surveillance | |
| AU609273B2 (en) | Random-filament, multi-directionally responsive marker for use in electronic article surveillance systems | |
| CA1301879C (en) | Economic, multi-directionally responsive marker for use in electronic article surveillance systems | |
| CA2170587C (en) | Multi-thread re-entrant marker with simultaneous switching | |
| US4495487A (en) | Amorphous antipilferage marker | |
| US5580664A (en) | Dual status thin-film eas marker having multiple magnetic layers | |
| EP0078401B1 (en) | Amorphous antipilferage marker | |
| CA2109643C (en) | Dual status thin-film eas marker | |
| WO2002018667A2 (en) | New amorphous fe-based alloys containing chromium | |
| JPH0435937A (en) | Magnetic composite parts | |
| CA2494255A1 (en) | Transverse magnetic field annealed amorphous magnetomechanical elements for use in electronic article surveillance system and method of making same | |
| WO1996001910A1 (en) | High response electronic article surveillance system responders and methods for producing same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |