US3801312A - Permanent magnet alloy using molybdenum and titanium - Google Patents
Permanent magnet alloy using molybdenum and titanium Download PDFInfo
- Publication number
- US3801312A US3801312A US00082500A US3801312DA US3801312A US 3801312 A US3801312 A US 3801312A US 00082500 A US00082500 A US 00082500A US 3801312D A US3801312D A US 3801312DA US 3801312 A US3801312 A US 3801312A
- Authority
- US
- United States
- Prior art keywords
- titanium
- molybdenum
- cobalt
- percent
- iron
- 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
Links
- 229910045601 alloy Inorganic materials 0.000 title claims abstract description 31
- 239000000956 alloy Substances 0.000 title claims abstract description 31
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 title abstract description 19
- 239000010936 titanium Substances 0.000 title abstract description 19
- 229910052719 titanium Inorganic materials 0.000 title abstract description 19
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 title abstract description 16
- 229910052750 molybdenum Inorganic materials 0.000 title abstract description 16
- 239000011733 molybdenum Substances 0.000 title abstract description 16
- 239000000203 mixture Substances 0.000 claims description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract description 36
- 229910017052 cobalt Inorganic materials 0.000 abstract description 18
- 239000010941 cobalt Substances 0.000 abstract description 18
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 abstract description 18
- 229910052742 iron Inorganic materials 0.000 abstract description 18
- 230000006698 induction Effects 0.000 abstract description 9
- FQMNUIZEFUVPNU-UHFFFAOYSA-N cobalt iron Chemical compound [Fe].[Co].[Co] FQMNUIZEFUVPNU-UHFFFAOYSA-N 0.000 description 3
- 239000011159 matrix material Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000032683 aging Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 229910000765 intermetallic Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- ZPZCREMGFMRIRR-UHFFFAOYSA-N molybdenum titanium Chemical compound [Ti].[Mo] ZPZCREMGFMRIRR-UHFFFAOYSA-N 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
Classifications
-
- 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
-
- 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
- H01F1/032—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 hard-magnetic materials
- H01F1/04—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 hard-magnetic materials metals or alloys
Definitions
- Appl- 82,500 A semihard permanent magnet alloy characterized by relatively high coercive force, relatively high residual [52] s 75/170, 148/3155 148/3157 induction, high ductility and low magnetostriction and 51 Int. Cl. C22c 19/00 consisting essentially of cobalt, iron, titanium and [58] Field f Search 75/170, 123 J, 123 K, 123 lybdenum. The molybdenum content of this alloy, as
- the relatively high coercive force of this type of alloy can be sharply increased at the cost of slightly reduced residual induction by adding molybdenum.
- the increased coercive force is an extremely useful characteristic and the slight reduction in residual induction can be tolerated.
- my alloy consists essentially of 3 6 percent by weight of molybdenum and 3 6 percent by weight of titanium, balance cobalt and iron, the ratio of cobalt to iron falling with the range 6521 to 7.5:] [This ratio is required to maintain very low magnetostriction and, thus, very low stress sensitivity of the magnetic properties]
- the titanium and molybdenum go into solution with the cobalt-iron matrix at high temperature and precipitate during the aging heat treatment as intermetallic compounds thereby increasing substantially the coercive force over that obtained by the use of titanium alone.
- the alloy is highly ductile and can be drawn readily into fine wire.
- the coercive force can range upwardly over 1 10 Orst.
- the alloy exhibits relatively high residual induction which ranges upward over 8,000 Gauss.
- This alloy was processed and tested as in Example I.
- the coercive force was 50 Orst; the residual induction was 10,600 Gauss; and the squareness ratio was 0.88.
- a semihard permanent magnet alloy consisting essentially of cobalt, iron, titanium and molybdenum, the total amount of cobalt and iron being from about 88 percent to about 94 percent by weight of said alloy and the weight ratio of cobalt to iron being from about 6.5:1 to about :1 and the amount of molybdenum and titanium each being from about 3 to about 6 percent by weight of said alloy.
Abstract
A semihard permanent magnet alloy characterized by relatively high coercive force, relatively high residual induction, high ductility and low magnetostriction and consisting essentially of cobalt, iron, titanium and molybdenum. The molybdenum content of this alloy, as expressed in percent by weight, falls within the approximate range 3 - 6 percent. The titanium content falls between 3 - 6 percent. The sum of the cobalt and iron falls within the approximate range 88 - 94 percent. The ratio by weight of cobalt to iron falls within the approximate range 6.5:1 to 7.5:1.
Description
United States Patent Steinitz 1 Apr. 2, 1974 [54] PERMANENT MAGNET ALLOY USING 3,511,639 5/1970 Chin et a1. 148/3155 X MOLYBDENUM AND TITANIUM 3,422,407 1/1969 Gould et a1. 148/3157 X [75] Inventor: Robert Steinitz, Montclair, NJ. Primary Examiner Richard 0 Dean [73] Assignee; Wilbur B, Driver Company Attorney, Agent, or Firm-Donald R. Castle [22] Filed: Oct. 20, 1970 ABSTRACT [21] Appl- 82,500 A semihard permanent magnet alloy characterized by relatively high coercive force, relatively high residual [52] s 75/170, 148/3155 148/3157 induction, high ductility and low magnetostriction and 51 Int. Cl. C22c 19/00 consisting essentially of cobalt, iron, titanium and [58] Field f Search 75/170, 123 J, 123 K, 123 lybdenum. The molybdenum content of this alloy, as
expressed in percent by weight, falls within the approximate range 3 6 percent. The titanium content falls between 3 6 percent. The sum of the cobalt and iron falls within the approximate range 88 94 percent. The ratio by weight of cobalt to iron falls within the approximate range 6.5:1 to 7.521.
3 Claims, No Drawings PERMANENT MAGNET ALLOY USING MOLYBDENUM AND TITANIUM BACKGROUND OF THE INVENTION Many types of electronic components and subsystems require the use of semihard permanent magnet alloys characterized by relatively high coercive force, low magnetostriction, high ductility and relatively high residual induction. Special alloys have been developed for this purpose. One type of known alloys consist primarily of cobalt and iron, the ratio by weight of cobalt to iron being approximately seven, together with a third metal, titanium.
I have discovered that the relatively high coercive force of this type of alloy can be sharply increased at the cost of slightly reduced residual induction by adding molybdenum. In certain critical electronic applications, the increased coercive force is an extremely useful characteristic and the slight reduction in residual induction can be tolerated.
SUMMARY OF THE INVENTION In accordance with my invention, my alloy consists essentially of 3 6 percent by weight of molybdenum and 3 6 percent by weight of titanium, balance cobalt and iron, the ratio of cobalt to iron falling with the range 6521 to 7.5:] [This ratio is required to maintain very low magnetostriction and, thus, very low stress sensitivity of the magnetic properties] In forming the alloy, the titanium and molybdenum go into solution with the cobalt-iron matrix at high temperature and precipitate during the aging heat treatment as intermetallic compounds thereby increasing substantially the coercive force over that obtained by the use of titanium alone. The alloy is highly ductile and can be drawn readily into fine wire. The coercive force can range upwardly over 1 10 Orst. Moreover the alloy exhibits relatively high residual induction which ranges upward over 8,000 Gauss.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In forming my alloys, a thorough homogenization at about 2,lF is required for all compositions. All alloys have to be cold worked, at least to between 85 95 percent and, preferably, between 95 99 percent. The higher the degree of cold work, the faster the molybdenum and titanium will coprecipitate in the cobaltiron matrix, whereby lower temperatures and shorter time periods can be employed in processing. Optimal heat treatment depends upon the desired magnetic properties; to some degree, temperature and time can be interchanged.
Further information will be found in the specific examples which follow:
EXAMPLE I An alloy homogenized and cold worked as described above was found to have the following composition:
cobalt 79% iron 11% molybdenum titanium 5% I The alloy was drawn into wire of 0.04 inches in diameter and heat treated at a temperature of 1,200F for a period of 2 hours. Measurements showed that the coercive force was 110 Orst; the residual induction was 8,300 Gauss; and the squareness ratio of the hysteresis curve was 0.87.
These results can be compared with those obtained from a known alloy processed and tested in the same manner and having the following composition:
cobalt 83% iron 12% titanium 5% This known alloy had a coercive force of 39 Orst, a
residual induction of 11000 Gauss and a squareness ratio of 0.87.
EXAMPLE II An alloy was produced having the following composition:
cobalt 80.5% iron I 1.5% molybdenum 3.0% titanium 5.0%
This alloy was processed and tested as in Example I. The coercive force was 50 Orst; the residual induction was 10,600 Gauss; and the squareness ratio was 0.88.
The combination of titanium and molybdenum in a cobalt-iron matrix produces a higher coercive force then either addition alone, without impeding the ductility of the alloy. Moreover, the total percent addition of both metals should fall within the range 6 12 percent to maintain the desired magnetic properties.
What is claimed is:
l. A semihard permanent magnet alloy consisting essentially of cobalt, iron, titanium and molybdenum, the total amount of cobalt and iron being from about 88 percent to about 94 percent by weight of said alloy and the weight ratio of cobalt to iron being from about 6.5:1 to about :1 and the amount of molybdenum and titanium each being from about 3 to about 6 percent by weight of said alloy.
2. An alloy in accordance with claim 1 having the following composition:
cobalt 79% iron I l% molybdenum 5% titanium 5% 3. An alloy in accordance with claim 1 having the following composition:
cobalt 80.5% iron 1 l .5% molybdenum 3.0% titanium 5.0%
Claims (2)
- 2. An alloy in accordance with claim 1 having the following composition:
- 3. An alloy in accordance with claim 1 having the following composition:
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US8250070A | 1970-10-20 | 1970-10-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3801312A true US3801312A (en) | 1974-04-02 |
Family
ID=22171610
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US00082500A Expired - Lifetime US3801312A (en) | 1970-10-20 | 1970-10-20 | Permanent magnet alloy using molybdenum and titanium |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3801312A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3983916A (en) * | 1973-11-12 | 1976-10-05 | Fujitsu Ltd. | Process for producing semi-hard co-nb-fl magnetic materials |
| US4211585A (en) * | 1976-03-10 | 1980-07-08 | Tokyo Shibaura Electric Co., Ltd. | Samarium-cobalt-copper-iron-titanium permanent magnets |
| US5484491A (en) * | 1991-09-30 | 1996-01-16 | Kabushiki Kaisha Toshiba | Ferromagnetic film |
-
1970
- 1970-10-20 US US00082500A patent/US3801312A/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3983916A (en) * | 1973-11-12 | 1976-10-05 | Fujitsu Ltd. | Process for producing semi-hard co-nb-fl magnetic materials |
| US4211585A (en) * | 1976-03-10 | 1980-07-08 | Tokyo Shibaura Electric Co., Ltd. | Samarium-cobalt-copper-iron-titanium permanent magnets |
| US5484491A (en) * | 1991-09-30 | 1996-01-16 | Kabushiki Kaisha Toshiba | Ferromagnetic film |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: CARPENTER TECHNOLOGY CORPORATION READING PENNSYLVA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:AMAX INC., A CORP OF NEW YORK;REEL/FRAME:004284/0609 Effective date: 19840427 |