[go: up one dir, main page]

US2768427A - Permanently magnetisable alloys and the production thereof - Google Patents

Permanently magnetisable alloys and the production thereof Download PDF

Info

Publication number
US2768427A
US2768427A US301611A US30161152A US2768427A US 2768427 A US2768427 A US 2768427A US 301611 A US301611 A US 301611A US 30161152 A US30161152 A US 30161152A US 2768427 A US2768427 A US 2768427A
Authority
US
United States
Prior art keywords
alloys
boron
production
iron
aluminium
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 - Lifetime
Application number
US301611A
Inventor
Frelm Fritz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Deutsche Edelstahlwerke AG
Original Assignee
Deutsche Edelstahlwerke AG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Deutsche Edelstahlwerke AG filed Critical Deutsche Edelstahlwerke AG
Application granted granted Critical
Publication of US2768427A publication Critical patent/US2768427A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C33/00Making ferrous alloys
    • C22C33/02Making ferrous alloys by powder metallurgy
    • C22C33/0257Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
    • C22C33/0278Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5%
    • C22C33/0285Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5% with Cr, Co, or Ni having a minimum content higher than 5%
    • YGENERAL 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
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S428/00Stock material or miscellaneous articles
    • Y10S428/922Static electricity metal bleed-off metallic stock
    • Y10S428/9265Special properties
    • Y10S428/928Magnetic property

Definitions

  • the present invention relates to permanently magnetisable alloys and the production thereof. It is known to produce permanent. magnet alloys b United States Patent m t a combination of the alloying elements nickel, aluminium and iron. These alloys may also contain cobalt and in addition one or more of the elements copper, titanium, silicon, tantalum and columbium.
  • Such alloys the properties of permanent magnetisatip n of which are produced by age-hardening mayhave contents of -40% nickel and 3 to 20% aluminium and where the said further elements are present, up to 40% cobalt, up to 20% copper, up to titanium, up to 3% silicon, up to 3% of zirconium and up to 5% of tantalum or columbium or up to 5% of the tantalum and columbium together, the remainder. being iron with the usual impurities, the proportions of the constituents of the alloy being so chosen where the optional elements are present that iron is present-up to at least 30%.
  • the '30 term consisting essentially of from 5% to 40% of nickel,
  • Alloys as aforesaid may be produced by mixing the metal constituents with. one another in powder form,
  • the alloying elements may be incorporated in the powder in the form of initial alloys of two or more components of the final alloy.
  • the production of the alloys by the sintering method generally guarantees the production of permanent magnetic properties corresponding to those of the alloys produced by the casting method, although there are exceptions to this rule.
  • the content of boron should be kept within the limits of 0.01 to 0.15%, and remarkable fesults have been obtained, as is shown from the examples which appear hereinafter, when the boron is selected from within the narrow range of such low percentages as from .01 to .10%. These percentages are alculated on the total quantity of the materials present n the composi-
  • the boron addition leads to an improvement in the permanent magnetic values in that the remanence values are higher in comparison with alloys without the boron 2,768,427 Patented Oct. 30, 1956 addition and the demagnetisation curve exhibits a more pronounced swelling, so that the energy product (BHm) is considerably increased.
  • BHmax values riiay be obtained which are at least or even 50% or more higher than the BHmu values of such alloys without the boron addition.
  • the alloy contains 12-18% nickel, 69% aluminium, 20 -35% cobalt, 2-6% copper, 0-8% titanium, 0.001-.15%I boron, and optionally 0.01-l.5% silicon, 0.0l-1.5% tantalum/ columbium, singly or severally, the remainder being iron with the usual impurities. Falling within this range of alloys are permanent magnet alloys which can be given Alloy I.-With0ut boron in the powder composition Percent Nickel 13.5
  • compositions according to the invention are as follows:
  • the al-loys according to the invention may also contain certain impurities in the iron remainder which are brought into the alloys by the starting materials employed. It is known that as ageneral rule these impurities should be kept as low as possible with the permanent magnet alloys of the type to which the invention relates, although it is not harmful in certain circumstances if they are occasionally present in relatively large quantities say in total up to 1.0%. This applies more especially as regards carbon, manganese, phosphorus, sulphur, chromium, tungsten, molybdenum, and the like.
  • the customary boron-free permanent magnet alloys which can be age-hardened have certain properties which are detrimental to their use.
  • the edges of the permanently magnetised elements made therefrom tend to break away especially when machining-the elements to finished form, e. g., during grinding, but even during subsequent use, when the permanent magnets are subjected to vibrations, striking and impact stresses. In many cases, this breaking away at the edges during mechanical treatment, and especially during grinding, cannot be tolerated since this leads to rejection and consequently uneconomic production.
  • permanent magnet elements which tend to break away at the edges during use cannot be employed for many purposes, because the permanently magnetised particles that break away. can penetrate into apparatus of which the permanent magnets are part, for example, into an instrument casing, gear, How of a liquid to be magnetically filtered, and the like. Such particles may then in certain circumstances cause considerable damage, especially by adhering to iron articles.
  • the alloys according to the invention have exceptional edge strength and resistance to breaking away, either during manufacture or during subsequent use. Manufacture is therefore substantially facilitated, because sintered elements as at present produced are incompatible with the method of machining which is most frequently employed with these permanent magnets, namely grinding.
  • the process for the production of alloys containing boron may, however, be essentially simplified by the fact that, without harming the permanent magnetic properties and without deleteriously affecting the mechanical properties, such as edge strength and insensitivity to winding, sinteringcan be carried out in a temperature range of 1300 to 1340" C. It is readily understandable that because of the wide'limits of the range, on the one l hand, the waste is obviously reduced and, on the other The known alloys without boron are in addition extremely sensitive to the maintenance of an optimum sintering temperature. With these alloys, it is necessary to maintain the temperature accurately to within about 3-6 (3., if the permanent magnetic properties in the products are constantly to have the same high values.
  • a sintered permanent magnet al-loy consisting essentially of from 5% to 40% of nickel, from 3% to 20% of aluminium, from 0.001% to 0.15% of boron and the remainder iron.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Hard Magnetic Materials (AREA)
  • Powder Metallurgy (AREA)

Description

7 tion.
The present invention relates to permanently magnetisable alloys and the production thereof. It is known to produce permanent. magnet alloys b United States Patent m t a combination of the alloying elements nickel, aluminium and iron. These alloys may also contain cobalt and in addition one or more of the elements copper, titanium, silicon, tantalum and columbium. Such alloys, the properties of permanent magnetisatip n of which are produced by age-hardening mayhave contents of -40% nickel and 3 to 20% aluminium and where the said further elements are present, up to 40% cobalt, up to 20% copper, up to titanium, up to 3% silicon, up to 3% of zirconium and up to 5% of tantalum or columbium or up to 5% of the tantalum and columbium together, the remainder. being iron with the usual impurities, the proportions of the constituents of the alloy being so chosen where the optional elements are present that iron is present-up to at least 30%. In the specification and claims hereof the '30 term consisting essentially of from 5% to 40% of nickel,
3% to aluminium and the remainder iron signifies that thesethree elements must be presentin the case of the nickel and aluminium within the aforesaid limits and in the case of iron in an amount at least 30%-,and that any one or more of the further elements above set forth may be present within the limits also above set forth.
Alloys as aforesaid may be produced by mixing the metal constituents with. one another in powder form,
pressing or moulding the mixture to shape and then sintering it. The alloying elements may be incorporated in the powder in the form of initial alloys of two or more components of the final alloy. The production of the alloys by the sintering method generally guarantees the production of permanent magnetic properties corresponding to those of the alloys produced by the casting method, although there are exceptions to this rule.
' form of a powdered alloy. Boron in the form of ferroboron with from 2% to 50% boron is advantageously chosen. a r v For example two ferro-alloys which areparticularly suitable are, ferroboron with about 16% boron and ferrobor'on with about 4% boron, it being immaterial if the initial alloy contains also a certain quantity of aluminium, for example, about.4%, and silicon, for example about 2%, in addition to boron.
in general, the content of boron should be kept within the limits of 0.01 to 0.15%, and remarkable fesults have been obtained, as is shown from the examples which appear hereinafter, when the boron is selected from within the narrow range of such low percentages as from .01 to .10%. These percentages are alculated on the total quantity of the materials present n the composi- The boron addition leads to an improvement in the permanent magnetic values in that the remanence values are higher in comparison with alloys without the boron 2,768,427 Patented Oct. 30, 1956 addition and the demagnetisation curve exhibits a more pronounced swelling, so that the energy product (BHm) is considerably increased. By means of the invention BHmax values riiay be obtained which are at least or even 50% or more higher than the BHmu values of such alloys without the boron addition.
Coming within the range to which the invention is applicable are all Alni and Alnico alloys at present in use. These alloys can be appreciably improved in their magnetic properties by the 'boron addition.
Particularly good results areobtained when the alloy contains 12-18% nickel, 69% aluminium, 20 -35% cobalt, 2-6% copper, 0-8% titanium, 0.001-.15%I boron, and optionally 0.01-l.5% silicon, 0.0l-1.5% tantalum/ columbium, singly or severally, the remainder being iron with the usual impurities. Falling within this range of alloys are permanent magnet alloys which can be given Alloy I.-With0ut boron in the powder composition Percent Nickel 13.5
Aluminium 8.0
Cobalt 24.0
Titanium 0.3
' Copper 3.0 Silicon 0.05
The remainder iron with the usual impurities, and in the specification and claims hereof the. term the remainder being iron" signifies that the said remainder may contain in small quantities any one or more of these impurities or other minor constituents.
'Alloy lI.-With boron in the powder composition t As Alloy l, but with 0.02% boron I have found that particularly good results can-be ob- After the sintering and suitable heat treatment, the following were obtained:
These magnetic properties with both alloys were measured in the preferred magnetic direction, which was produced by the known method of cooling in a magnetic field. The values are of course correspondingly lower in both cases if the alloys are not subjected to a treatment for the production of apreferred direction of magnetisation.
Examples of further compositions according to the invention are as follows:
Al N1 Tl on B Co 11 21 1.5 2.5 0.03 10.5 21 0.6 0.00 0.02 0.5 s '11 2.25 a 0.07s 16 -20% higher and the third 30% or more higher than corresponding alloys without boron.
The al-loys according to the invention may also contain certain impurities in the iron remainder which are brought into the alloys by the starting materials employed. It is known that as ageneral rule these impurities should be kept as low as possible with the permanent magnet alloys of the type to which the invention relates, although it is not harmful in certain circumstances if they are occasionally present in relatively large quantities say in total up to 1.0%. This applies more especially as regards carbon, manganese, phosphorus, sulphur, chromium, tungsten, molybdenum, and the like.
As is known, the customary boron-free permanent magnet alloys which can be age-hardened have certain properties which are detrimental to their use. In particular, the edges of the permanently magnetised elements made therefrom tend to break away especially when machining-the elements to finished form, e. g., during grinding, but even during subsequent use, when the permanent magnets are subjected to vibrations, striking and impact stresses. In many cases, this breaking away at the edges during mechanical treatment, and especially during grinding, cannot be tolerated since this leads to rejection and consequently uneconomic production. Furthermore, it will readily be appreciated that permanent magnet elements which tend to break away at the edges during use cannot be employed for many purposes, because the permanently magnetised particles that break away. can penetrate into apparatus of which the permanent magnets are part, for example, into an instrument casing, gear, How of a liquid to be magnetically filtered, and the like. Such particles may then in certain circumstances cause considerable damage, especially by adhering to iron articles.
The alloys according to the invention, on the contrary, have exceptional edge strength and resistance to breaking away, either during manufacture or during subsequent use. Manufacture is therefore substantially facilitated, because sintered elements as at present produced are incompatible with the method of machining which is most frequently employed with these permanent magnets, namely grinding.
purposes. The process for the production of alloys containing boron may, however, be essentially simplified by the fact that, without harming the permanent magnetic properties and without deleteriously affecting the mechanical properties, such as edge strength and insensitivity to winding, sinteringcan be carried out in a temperature range of 1300 to 1340" C. It is readily understandable that because of the wide'limits of the range, on the one l hand, the waste is obviously reduced and, on the other The known alloys without boron are in addition extremely sensitive to the maintenance of an optimum sintering temperature. With these alloys, it is necessary to maintain the temperature accurately to within about 3-6 (3., if the permanent magnetic properties in the products are constantly to have the same high values.
This makes production diificult and frequently results in rejects which cannot always be used for secondary hand, exceptionally careful supervision of the temperature is not necessary for the operation of the sintering furnaces.
What I claim is:
1. Process for improving the structure and magnetic properties of age-hardenable permanent magnet alloys essentially made by sintering powdered material consisting essentially of from 5% to '40% of nickel, from 3% to 20% of aluminium and the remainder iron, which consists in incorporating bororf in an amount of from 0.001% to 0.15% in the said material and then effecting the sintering operation on the boron-containing material.
2. Process according to claim 1 in which the boron is incorporated in the powdered material in theform of powdered ferroboron containing from 2% to 50% boron and in an amount such that the boron content of the mixture shall be from 0.001% to 0.15% of the said mixture.
3. A sintered permanent magnet al-loy consisting essentially of from 5% to 40% of nickel, from 3% to 20% of aluminium, from 0.001% to 0.15% of boron and the remainder iron. 1
4. A sintered permanent magnet alloy according to claim 3 in which the said boron content is from 0.01% to 0.10%.
References Cited in the file of this patent UNITED STATES PATENTS

Claims (1)

1. PROCESS FOR IMPROVING THE STRUCTURE AND MAGNETIC PROPERTIES OF AGE-HARDENABLE PERMANENT MAGNET ALLOYS ESSENTIALLY MADE BY SINTERING POWDERED MATERIAL CONSISTING ESSENTIALLY OF FROM 5% TO 40% OF NICKEL, FROM 3% TO 20% OF ALUMINIUM AND THE REMAINDER IRON, WHICH CONSISTS INCORPORATING BORON IN AN AMOUNT OF FROM 0.001% TO 0.15% IN THE SAID MATERIAL AND THEN EFFECTING THE SINTERING OPERATION ON THE BORON-CONTAINING MATERIAL.
US301611A 1951-08-06 1952-07-29 Permanently magnetisable alloys and the production thereof Expired - Lifetime US2768427A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2768427X 1951-08-06

Publications (1)

Publication Number Publication Date
US2768427A true US2768427A (en) 1956-10-30

Family

ID=7998013

Family Applications (1)

Application Number Title Priority Date Filing Date
US301611A Expired - Lifetime US2768427A (en) 1951-08-06 1952-07-29 Permanently magnetisable alloys and the production thereof

Country Status (1)

Country Link
US (1) US2768427A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2978323A (en) * 1956-12-17 1961-04-04 Gen Aniline & Film Corp Alloyed flocks from metal carbonyls and halides
US2983997A (en) * 1956-12-17 1961-05-16 Gen Aniline & Film Corp Sintered magnetizable body from metal carbonyls and halides
US4117058A (en) * 1976-12-03 1978-09-26 General Motors Corporation Method of making boron containing strontium ferrite

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1154701A (en) * 1913-08-25 1915-09-28 Ernst August Krueger Process of producing tungsten filaments.
US1633258A (en) * 1925-10-08 1927-06-21 Clemens A Laise Refractory metal alloy of high density and high melting point and method of making the same
FR749713A (en) * 1932-02-06 1933-07-28 Kinzoku Zairyo Kenkyusho Magnetic alloy
US1968067A (en) * 1930-05-29 1934-07-31 Ramet Corp Of America Alloy and method of making same
US2107122A (en) * 1934-09-10 1938-02-01 Clemens A Laise Composition of matter
US2192743A (en) * 1937-09-17 1940-03-05 Gen Electric Sintered permanent magnet
US2225424A (en) * 1940-04-10 1940-12-17 American Electro Metal Corp Manufacture of alloys, in particular steel alloys
US2384450A (en) * 1942-06-04 1945-09-11 Int Nickel Co Alloy for permanent magnets
US2401087A (en) * 1945-11-08 1946-05-28 J K Smit & Sons Inc Diamond drill bit
US2499862A (en) * 1948-03-16 1950-03-07 Crucible Steel Co America Permanent magnets and alloys therefor
US2694790A (en) * 1948-02-17 1954-11-16 Gen Electric Sintered anisotropic permanent magnet

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1154701A (en) * 1913-08-25 1915-09-28 Ernst August Krueger Process of producing tungsten filaments.
US1633258A (en) * 1925-10-08 1927-06-21 Clemens A Laise Refractory metal alloy of high density and high melting point and method of making the same
US1968067A (en) * 1930-05-29 1934-07-31 Ramet Corp Of America Alloy and method of making same
FR749713A (en) * 1932-02-06 1933-07-28 Kinzoku Zairyo Kenkyusho Magnetic alloy
US2107122A (en) * 1934-09-10 1938-02-01 Clemens A Laise Composition of matter
US2192743A (en) * 1937-09-17 1940-03-05 Gen Electric Sintered permanent magnet
US2225424A (en) * 1940-04-10 1940-12-17 American Electro Metal Corp Manufacture of alloys, in particular steel alloys
US2384450A (en) * 1942-06-04 1945-09-11 Int Nickel Co Alloy for permanent magnets
US2401087A (en) * 1945-11-08 1946-05-28 J K Smit & Sons Inc Diamond drill bit
US2694790A (en) * 1948-02-17 1954-11-16 Gen Electric Sintered anisotropic permanent magnet
US2499862A (en) * 1948-03-16 1950-03-07 Crucible Steel Co America Permanent magnets and alloys therefor

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2978323A (en) * 1956-12-17 1961-04-04 Gen Aniline & Film Corp Alloyed flocks from metal carbonyls and halides
US2983997A (en) * 1956-12-17 1961-05-16 Gen Aniline & Film Corp Sintered magnetizable body from metal carbonyls and halides
US4117058A (en) * 1976-12-03 1978-09-26 General Motors Corporation Method of making boron containing strontium ferrite

Similar Documents

Publication Publication Date Title
US2768427A (en) Permanently magnetisable alloys and the production thereof
US2061370A (en) Heat resisting article
GB734597A (en) Permanent magnet alloys and the production thereof
US3147112A (en) Ferromagnetic mn-ga alloy and method of production
US3730784A (en) Method of making manganese-aluminum-carbon ternary alloys for permanent magnets
JPH06228717A (en) Silicon stainless steel
US2694790A (en) Sintered anisotropic permanent magnet
US4721538A (en) Permanent magnet alloy
US2797161A (en) Magnet alloy
US2384450A (en) Alloy for permanent magnets
JPS59132105A (en) Permanent magnet
US2673310A (en) Permanent magnet
US2694167A (en) Permanent magnet alloy
US3432279A (en) Molded magnetic powdered metal
US2395285A (en) Alloy
US3463678A (en) Method for improving magnetic properties of cobalt-yttrium or cobalt-rare earth metal compounds
EP0185439B1 (en) Permanent magnet alloy
US3301720A (en) Treatment of material for hysteresis application
US2027996A (en) Strong permanent magnet with cobalt
CN104593660A (en) Method for alloying Ga element through neodymium-iron-boron permanent magnet material
US2427018A (en) Permanent magnet materials
SU141174A1 (en) Iron-based hard magnetic alloy
US3801312A (en) Permanent magnet alloy using molybdenum and titanium
CN103468984A (en) Smelting technique of environment-friendly food machine material
US4789521A (en) Permanent magnet alloy