CN1032262A - Microstructure Optimization of Fe-Nd-B Sintered Magnets - Google Patents
Microstructure Optimization of Fe-Nd-B Sintered Magnets Download PDFInfo
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- CN1032262A CN1032262A CN 88106179 CN88106179A CN1032262A CN 1032262 A CN1032262 A CN 1032262A CN 88106179 CN88106179 CN 88106179 CN 88106179 A CN88106179 A CN 88106179A CN 1032262 A CN1032262 A CN 1032262A
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- 238000005457 optimization Methods 0.000 title 1
- 239000012071 phase Substances 0.000 claims abstract description 31
- 239000000203 mixture Substances 0.000 claims abstract description 19
- 230000005291 magnetic effect Effects 0.000 claims abstract description 14
- 239000007791 liquid phase Substances 0.000 claims abstract description 3
- 229910052692 Dysprosium Inorganic materials 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- 229910052771 Terbium Inorganic materials 0.000 claims description 4
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- 230000005415 magnetization Effects 0.000 claims description 2
- 238000005245 sintering Methods 0.000 abstract description 10
- 239000000843 powder Substances 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000005275 alloying Methods 0.000 description 2
- 230000005294 ferromagnetic effect Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000008188 pellet Substances 0.000 description 2
- 238000010587 phase diagram Methods 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 229910017493 Nd 2 O 3 Inorganic materials 0.000 description 1
- 229910052779 Neodymium Inorganic materials 0.000 description 1
- QJVKUMXDEUEQLH-UHFFFAOYSA-N [B].[Fe].[Nd] Chemical compound [B].[Fe].[Nd] QJVKUMXDEUEQLH-UHFFFAOYSA-N 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 229910001172 neodymium magnet Inorganic materials 0.000 description 1
- 230000005408 paramagnetism Effects 0.000 description 1
- 238000004663 powder metallurgy Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
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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
- H01F1/032—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
- H01F1/047—Alloys characterised by their composition
- H01F1/053—Alloys characterised by their composition containing rare earth metals
- H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
- H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
- H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
- H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
- H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
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Abstract
新型Fe—Nd—B烧结磁铁的特点是其组织中 无0.5μm以上的Fe4NdB4体(η相)，烧结温度下其 组成处于Fe14Nd2B()和富含Nd并且655℃以上 为液态的相(L相)两相区域，该磁铁的磁性，特别是 矫顽磁场强度HCJ和其温度系数大为改善。
The characteristic of the new Fe—Nd—B sintered magnet is that there is no Fe 4 NdB 4 body (η phase) above 0.5 μm in its structure, and its composition is Fe 14 Nd 2 B() and Nd-rich at 655°C at the sintering temperature In the two-phase region above the liquid phase (L phase), the magnetic properties of the magnet, especially the coercive magnetic field strength H CJ and its temperature coefficient are greatly improved.
Description
本发明涉及性能得到改善的铁-钕-硼（Fe-Nd-B）烧结磁铁及其制法。The present invention relates to iron-neodymium-boron (Fe-Nd-B) sintered magnets with improved properties and a method for their preparation.
自从M.Sagawa在J.Appl.Phys.55，2083（1984）中首次报道Nd-Fe-B新型永磁材料以来，为进一步提高这些材料的性能，又进行了许多研究。这些试验的基础是，Fe-Nd-B磁铁，特别是这种组成的磁铁，室温下的特征是磁特性值特别高。但在具有这一优点的同时，也还表现出缺点，其温度稳定性，主要是矫顽磁场强度HCJ的温度稳定性不能令人满意，并且这种磁铁在加温机器中的应用受到限制。因此，为了在该领域里工业上得以应用，就必须对该磁铁进行改进，以使其在高达200℃也可用于强反向场（Gegenfeldern）。Since M. Sagawa first reported Nd-Fe-B new permanent magnet materials in J.Appl.Phys.55, 2083 (1984), many studies have been carried out to further improve the performance of these materials. The basis of these experiments is that Fe-Nd-B magnets, especially magnets of this composition, are characterized by particularly high magnetic property values at room temperature. But while having this advantage, it also shows disadvantages, its temperature stability, mainly the temperature stability of the coercive magnetic field strength H CJ is not satisfactory, and the application of this magnet in heating machines is limited . Therefore, for industrial use in this field, the magnet must be modified so that it can also be used in strong reverse fields up to 200°C.
性能不能令人满意，特别是与理论值比较起来其矫顽磁场强度低的主要原因之一是，存在非铁磁组织成分。这会引起强磁性杂散场，从而容易在非磁性影响近区形成非磁性籽晶。这种自动去磁效应在升温条件下总是很强，因为本征矫顽磁场强度象杂散场效应一样随温度变化很大。One of the main reasons for the unsatisfactory performance, especially the low coercive field strength compared to the theoretical value, is the presence of non-ferromagnetic constituents. This induces a strong magnetic stray field, which easily forms nonmagnetic seeds in the vicinity of the nonmagnetic influence. This self-demagnetization effect is always strong under elevated temperature conditions, because the intrinsic coercive field strength varies greatly with temperature like the stray field effect.
在制成组成为例如Fe77 Nd15 B8的烧结磁铁中，主要有3相，即In sintered magnets made of compositions such as Fe77 Nd15 B8, there are mainly 3 phases, namely
1.Fe14 Nd2 B，以下称为φ相，是磁性的载体，1. Fe14 Nd2 B, hereinafter referred to as φ phase, is a magnetic carrier,
2.富含Nd相（基本上由Nd，Nd2O3组成），以下称为L相，在655℃以上为液态，不仅可在液相烧结过程中达到良好的浓缩，而且可使相邻φ体达到磁性退耦，2. The Nd-rich phase (basically composed of Nd, Nd 2 O 3 ), hereinafter referred to as the L phase, is liquid above 655 ° C, not only can achieve good concentration during liquid phase sintering, but also can make the adjacent φ body achieves magnetic decoupling,
3.Fe4Nd B4，以下称为η相，13K以上具有顺磁性，因此可认为是出现上述缺点的主要原因。3. Fe4Nd B4, hereinafter referred to as η phase, has paramagnetism above 13K, so it can be considered as the main reason for the above shortcomings.
在所述已知典型磁铁中，组成为例如η相体积占5～8%，L相约占 10%，而其余由铁磁φ相组成。In the known typical magnet, the composition is such that, for example, the η phase accounts for 5 to 8% by volume, the L phase accounts for about 10%, and the rest is composed of the ferromagnetic φ phase.
按照本专业领域的观点，在Fe-Nd-B磁铁制造过程中，不希望存在的η相的形成不可阻止，因此必须认为是不可避免的（R.K.Mishra，J.Appl.Phys.59，2244（1986））。From the point of view of the professional field, the formation of the undesired η phase during the manufacture of Fe-Nd-B magnets cannot be prevented and must therefore be considered unavoidable (R.K.Mishra, J.Appl.Phys.59, 2244( 1986)).
本发明的目的是改善Fe-Nd-B烧结磁铁的磁性，特别是改善矫顽磁场强度和其与温度的关系，并且增强剩磁。The purpose of the present invention is to improve the magnetic properties of Fe-Nd-B sintered magnets, especially to improve the coercive field strength and its relationship with temperature, and to enhance the remanence.
根据本发明，这一目的是通过Fe-Nd-B烧结磁铁达到的，其特征是其组织中无0.5μm以上的Fe4Nd B4体（η相），烧结温度下其组成处于Fe14 Nd2B（φ相）和富含Nd并且655℃以上为液态的相（L相）两相区域。According to the present invention, this object is achieved by Fe-Nd-B sintered magnets, which are characterized in that there is no Fe4Nd B4 body (η phase) above 0.5 μm in its structure, and its composition is in Fe14 Nd2B (φ phase) at the sintering temperature and the Nd-rich phase (L phase) that is liquid above 655°C.
由于本发明烧结磁铁中缺乏更大的η体，因此可大大改善上述磁性。Due to the lack of larger η body in the sintered magnet of the present invention, the above-mentioned magnetic properties can be greatly improved.
按照已知的Fe-Nd-B三相图（K.H.J.Buschow et al.，Philips J.Res.40，230（1985）），烧结温度下不存在L+φ两相区域。但是，现出人意料地发现并构成本发明基础的是，烧结温度下主要为两相区域，并且可这样来选择磁铁合金的组成，即在约1000-1080℃烧结温度下处于此两相区域。图1以等温面形式示出1060℃下的这种新相图，其中用影线画出上述两相。在1060℃的烧结温度下，两相合金就一定处于此三角形内，该三角形由以下各点限定：According to the known Fe-Nd-B three-phase diagram (K.H.J.Buschow et al., Philips J.Res.40, 230 (1985)), there is no L+φ two-phase region at the sintering temperature. However, it has now been surprisingly found and forms the basis of the present invention that at sintering temperatures there is a predominantly two-phase region and that the composition of the magnet alloy can be selected such that it is in this two-phase region at sintering temperatures of about 1000-1080°C. Figure 1 shows this new phase diagram at 1060°C in the form of an isothermal surface, where the two phases mentioned above are hatched. At a sintering temperature of 1060°C, the two-phase alloy must lie within this triangle, which is defined by the following points:
Fe82.3 Nd11.8 B5.9，Fe82.3 Nd11.8 B5.9,
Fe58.5 N38 B3.5和Fe58.5 N38 B3.5 and
Fe60.5 Nd27 B12.5。Fe60.5 Nd27 B12.5.
因此，根据本发明，该组成范围内的磁铁为优选。Therefore, according to the present invention, magnets within this composition range are preferred.
按照本发明，两相区域中于烧结温度下出现的磁铁在烧结温度冷却过程中仅在组织中形成极为细小的η体。由于缺乏过去不可避免的大η体，因此可使性能得到改善。图2a和2b示出已知磁铁（2a）和本发明磁铁（2b）之间的组织结构差别。图2a磁铁的组成对应于式Fe77 Nd15 B8。φ相光 亮，η相呈灰色，L相为黑色。图2b的磁铁对应于组成Fe75 Nd18.5 B5.6。这里不再能见到出现灰色的η相。这种组成为Fe75 Nd18.5 B的烧结磁铁在室温下呈现出以下的典型性能：According to the invention, the magnets present in the two-phase region at the sintering temperature only form extremely fine η bodies in the structure during cooling at the sintering temperature. Performance is improved due to the absence of large η bodies that were unavoidable in the past. Figures 2a and 2b show the structural differences between the known magnet (2a) and the inventive magnet (2b). The composition of the magnet in Figure 2a corresponds to the formula Fe77 Nd15 B8. The φ phase is bright, the η phase is gray, and the L phase is black. The magnet of Fig. 2b corresponds to the composition Fe75 Nd18.5 B5.6. Here the gray η phase is no longer visible. This sintered magnet with composition Fe75 Nd18.5 B exhibits the following typical properties at room temperature:
剩磁Br＝1.1 TRemanence Br＝1.1 T
矫顽磁场强度HCJ＝1040kA/m。The coercive magnetic field strength H CJ =1040kA/m.
这些值对本发明烧结磁铁来说是典型的并且就上述特定组成来说其偏差一般不会超过5%。These values are typical for the sintered magnets of the present invention and generally do not deviate by more than 5% for the specific composition mentioned above.
本发明烧结磁铁的特殊优点是大大改善了磁化矫顽磁场强度HCJ的温度系数。已知磁铁的该系数在-0.7～-0.9%/K以上，而本发明磁铁的该系数为-0.5%/K，其中上下偏差根据组成的不同而可为0.1%/K。The special advantage of the sintered magnet of the present invention is that the temperature coefficient of magnetization coercive field strength H CJ is greatly improved. The coefficient of the known magnet is above -0.7～-0.9%/K, while the coefficient of the magnet of the present invention is -0.5%/K, wherein the upper and lower deviations can be 0.1%/K according to the composition.
本发明烧结磁铁中除了基本成分Fe-Nd-B而外还可加入其它合金元素，特别是Co，Al，Dy，Tb和C中的一种和多种，其用量可从文献中得知，从而影响晶体各向异性，居里温度和磁矩等性能。优选的本发明磁铁中含0～20At.-% Co，0～15At.-% Al，0～20At.-% Dy，0～20At.-%Tb和0～12.5 At.-%C。In the sintered magnet of the present invention, in addition to the basic component Fe-Nd-B, other alloying elements can be added, especially one or more of Co, Al, Dy, Tb and C, and its consumption can be known from the literature. Thus affecting properties such as crystal anisotropy, Curie temperature and magnetic moment. The preferred magnet of the present invention contains 0-20 At.-% Co, 0-15 At.-% Al, 0-20 At.-% Dy, 0-20 At.-% Tb and 0-12.5 At.-% C.
本发明两相磁铁中加入一种或多种上述其它合金元素时的主要优点可从图3中看出，其中对现有技术中3种Fe-Nd-B磁铁的矫顽磁场强度的温度关系加或不加Al或Dy的对应组成本发明磁铁进行了比较。现有技术中3相磁铁组成为Nd15 Fe77 B8，Nd15（Fe75 A12）B8和Nd13.5 Dy1.5Fe77 B8。对应本发明2相磁铁组成为Nd18.5 Fe75 B6.5，Nd18.5（Fe73 A12）B6.5和Nd16.65 Dy1.85 Fe75 B6.5。The main advantage when adding one or more above-mentioned other alloying elements in the two-phase magnet of the present invention can be seen from Fig. 3, wherein to the temperature relation of the coercive field intensity of 3 kinds of Fe-Nd-B magnets in the prior art The magnets of the present invention with or without Al or Dy were compared. The three-phase magnet composition in the prior art is Nd15 Fe77 B8, Nd15 (Fe75 A12) B8 and Nd13.5 Dy1.5Fe77 B8. The composition of the two-phase magnet corresponding to the present invention is Nd18.5 Fe75 B6.5, Nd18.5 (Fe73 A12) B6.5 and Nd16.65 Dy1.85 Fe75 B6.5.
本发明烧结磁铁的制造方法是从按已知的粉末冶金方式将各纯组分（纯度99%或更高）预合金化开始。优选的制造方法中，在垂直于压制方向的方向上向粉末混合物加一磁场，将粉末轴向压制成生球团，并在惰性气氛中，优选是在稀有气体中于1040-1080℃下烧结该生球团矿，然后于500-700℃下回火。The method of manufacturing the sintered magnets of the present invention starts with the prealloying of the pure components (purity 99% or higher) in a known powder metallurgy manner. In a preferred manufacturing method, a magnetic field is applied to the powder mixture in a direction perpendicular to the pressing direction, the powder is axially pressed into green pellets, and sintered at 1040-1080°C in an inert atmosphere, preferably in a rare gas The green pellets are then tempered at 500-700°C.
为制得各组分的粉末混合物，可采用例如稀有气体中的WC-Co-振动球磨机。通过在垂直于压制方向的方向上加0.4～0.6T的磁场，可使粉末呈直线排列，然后再轴向压缩。压力优选为500-800MPa，特别是450-550MPa。To prepare a powder mixture of the individual components, for example a WC-Co-vibrating ball mill in a rare gas can be used. By applying a magnetic field of 0.4-0.6T in the direction perpendicular to the pressing direction, the powder can be arranged in a straight line, and then compressed axially. The pressure is preferably 500-800 MPa, especially 450-550 MPa.
烧结优选在1050-1070℃范围内进行，并可根据所用条件的不同而持续约0.5～3小时。然后一般在500-700℃下进行退火，持续时间一般为0.2～4小时。Sintering is preferably carried out at a temperature in the range of 1050-1070° C. and may last for about 0.5 to 3 hours depending on the conditions used. Then annealing is generally carried out at 500-700°C, and the duration is generally 0.2-4 hours.
Claims (7)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3729361.3 | 1987-09-02 | ||
| DE19873729361 DE3729361A1 (en) | 1987-09-02 | 1987-09-02 | OPTIMIZATION OF THE STRUCTURE OF THE FE-ND-B BASE SINTER MAGNET |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1032262A true CN1032262A (en) | 1989-04-05 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 88106179 Pending CN1032262A (en) | 1987-09-02 | 1988-08-22 | Microstructure Optimization of Fe-Nd-B Sintered Magnets |
Country Status (3)
| Country | Link |
|---|---|
| CN (1) | CN1032262A (en) |
| DE (1) | DE3729361A1 (en) |
| WO (1) | WO1989002156A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT399415B (en) * | 1991-03-18 | 1995-05-26 | Boehler Ybbstalwerke | METHOD FOR PRODUCING RARE EARTH-CONTAINING PERMANENT MAGNET (S) (MATERIALS) |
| DE4142160C1 (en) * | 1991-12-20 | 1993-03-11 | Heraeus Elektrochemie Gmbh, 6450 Hanau, De | |
| DE19945943B4 (en) * | 1999-09-24 | 2005-06-02 | Vacuumschmelze Gmbh | Borarme Nd-Fe-B alloy and process for its preparation |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6187825A (en) * | 1984-10-05 | 1986-05-06 | Hitachi Metals Ltd | Manufacture of permanent magnet material |
| JPH0789521B2 (en) * | 1985-03-28 | 1995-09-27 | 株式会社東芝 | Rare earth iron permanent magnet |
-
1987
- 1987-09-02 DE DE19873729361 patent/DE3729361A1/en not_active Withdrawn
-
1988
- 1988-06-23 WO PCT/EP1988/000555 patent/WO1989002156A1/en unknown
- 1988-08-22 CN CN 88106179 patent/CN1032262A/en active Pending
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| Publication number | Publication date |
|---|---|
| WO1989002156A1 (en) | 1989-03-09 |
| DE3729361A1 (en) | 1989-03-16 |
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