CN87105186A

CN87105186A - Permanent magnet with good thermal stability

Info

Publication number: CN87105186A
Application number: CN87105186.9A
Authority: CN
Inventors: 德·永雅亮; 遠藤実; 小暮浩
Original assignee: Hitachi Metals Ltd
Current assignee: Proterial Ltd
Priority date: 1986-07-23
Filing date: 1987-07-23
Publication date: 1988-02-03
Anticipated expiration: 2002-07-23
Also published as: DE3750661T2; CN1036554C; EP0421488B1; KR910001065B1; EP0421488A3; JP2751109B2; EP0258609A2; DE3783975T2; JPS647503A; DE3750661D1; DE3783975D1; KR880002202A; EP0258609B1; EP0421488A2; EP0258609A3

Abstract

A permanent magnet having good thermal stability, consisting essentially of a composition expressed by the following general formula:

R[Fe_{1_x_y_z}CoxB_yGa_z]_A

wherein R can be only neodymium or one or more rare earth elements mainly consisting of neodymium, praseodymium or cerium, x is more than or equal to 0 and less than or equal to 0.7, y is more than or equal to 0.02 and less than or equal to 0.3, z is more than or equal to 0.001 and less than or equal to 0.15, and A is more than or equal to 4.0 and less than or equal to 7.5.

The permanent magnet may also contain one or more additional elements selected from the group consisting of niobium, tungsten, vanadium, tantalum, and molybdenum. The permanent magnet has a high coercive force and a high Curie temperature, and thus has good thermal stability.

Description

The present invention relates to the rare-earth permanent magnet material, particularly the rare-earth iron-boron permanent magnet material of good thermal stability.

Developed the new prescription (article " with neodymium and iron is the permanent magnet new material of main component " that Japan Patent open 59-46008,59-64733 and people such as 59-89401 and M.Sagawa in one nine eight four year five ten five volume six phase 2083rd page " applicating physical magazine " write) of magnetic property so far than the better rare-earth iron-boron permanent magnet of Rare-Earth Cobalt permanent magnet material.According to these documents, for example a kind of Nd ₁₅Fe ₇₇B ₈(Nd(Fe _0.91B _0.09) _5.67) alloy have such magnetic property: (BH) is maximum near 35 mega gaussorersteds, and iHc is near 10 kilo-oersteds.But the Curie temperature of alkene unmanufactured iron boron magnets is low, thereby their poor heat stability.For addressing these problems, the someone attempts to improve Curie temperature (the open 59-64733 of Japan Patent) by adding cobalt.Specifically, the Curie temperature of rare-earth iron-boron permanent magnet is about 300 ℃, be up to 370 ℃ (the open 59-46008 of Japan Patent), and the part iron that replaces in the rare-earth iron-boron magnet with cobalt can make Curie temperature bring up to 400～800 ℃ (the open 59-64733 of Japan Patent).Add the coercive force iHc that cobalt has reduced rare-earth iron-boron magnet simultaneously.

Past also the someone attempt to wait and improve coercive force by adding aluminium, titanium, vanadium, chromium, manganese, zinc, hafnium, niobium, tantalum, molybdenum, germanium, antimony, tin, bismuth, nickel.Someone pointed out, aluminium effective especially aspect the raising coercive force (the open 59-89401 of Japan Patent).But, add these elements in a large number and can reduce resideual flux density Br, thereby (BH) maximum is also descended because these elements all are nonmagnetic elements except that nickel.

In addition, the someone proposed to use the heavy rare earth element replacement part neodymium such as terbium, dysprosium and holmium to keep high (BH) maximum (the open 60-32306 and 60-34005 of Japan Patent) simultaneously to improve coercive force.Replacing the part neodymium with heavy rare earth element is to make coercive force bring up to 12～18 kilo-oersteds from about 9 kilo-oersteds under (BH) the most about 30 mega gaussorersteds, but because heavy rare earth element is extremely expensive, thereby can improve the cost of rare-earth iron-boron magnet with a large amount of instead of part neodymiums of this class heavy rare earth element, this is that we are undesirable.

In addition, the someone proposed to add the thermal stability that cobalt and aluminium improves rare-earth iron-boron magnet (people such as T.Mizoguchi, the 1309th page of " Applied Physics communication " in 1986 48 volume).Can improve Curie temperature Tc with cobalt instead of part iron, but reduce iHc simultaneously, the chances are for this because Nd (Fe, Co) occurs at crystal boundary ₂Ferromagnetic precipitated phase, thus the nucleus that forms reverse farmland forms the district.Add aluminium and add cobalt simultaneously, can form non magnetic Nd (Fe, Co, Al) ₂Phase, this has the nucleus that suppresses reverse magnetic domain mutually and forms the effect that the district produces.But because the adding of aluminium greatly reduces Curie temperature Tc, thereby contains the rare-earth iron-boron magnet of cobalt and aluminium, its thermal stability is up to 100 ℃ or above temperature variation inevitably just.In addition, the coercive force of this magnet has only about 9 kilo-oersteds.

Therefore an object of the present invention is to provide a kind of Curie temperature increases and has the rare-earth iron-boron permanent magnet that enough coercive forces thereby thermal stability improve.

The present inventor furthers investigate at above-mentioned purpose with the people, found that, adds gallium, or cobalt and gallium add together, can produce the rare-earth iron-boron magnet that Curie temperature is higher, coercive force is enough thereby thermal stability is high, cost is cheap.

In other words, the permanent magnet of Heat stability is good of the present invention is made up of the following composition of its expression formula basically:

R〔Fe _1-x-y-zCo _xB _yGa _z〕A

Wherein R only is a neodymium, or one or more rare earth element of mainly being made up of neodymium, praseodymium or cerium, 0≤X≤0.7,0.02≤Y≤0.3,0.001≤Z≤0.15,4.0≤A≤7.5.

Fig. 1 is the relation curve that the irreversible flux loss of neodymium iron boron, nd-dy-fe-b and neodymium iron boron gallium magnet changes with heating-up temperature.

Fig. 2 is the relation curve that the irreversible flux loss of neodymium iron cobalt boron, neodymium dysprosium iron cobalt boron and neodymium iron cobalt boron gallium magnet changes with heating-up temperature.

Fig. 3 is the relation curve that the irreversible flux loss of neodymium iron cobalt boron, neodymium iron cobalt boron gallium and neodymium iron cobalt boron gallium tungsten magnet changes with heating-up temperature.

Fig. 4 is Nd (Fe _0.85-xCo _0.06B _0.08Ga _xW _0.01) _5.4The relation curve that changes with heating-up temperature of irreversible magnetic flux magnetic loss.

Fig. 5 is that (second) quenching → heat treatment fast → hot pressing and (third) are met quenching → HIP soon with (first) quenching → heat treatment fast → resin-bonding ^*The relation curve that the magnet of the method preparation of → upsetting changes with heating-up temperature.Annotate: the isobaric hot pressing of * HIP=

Fig. 6 has compared the magnetic property of magnet such as neodymium dysprosium iron cobalt boron, neodymium iron cobalt boron aluminium and neodymium iron cobalt boron gallium.

Fig. 7 is Nd (Fe _0.72Co _0.2B _0.08) _5.6, Nd _0.8Dy _0.2(Fe _0.72Co _0.2B _0.08) _5.6, Nd (Fe _0.67Co _0.2B _0.08Al _0.05) _5.6And Nd (Fe _0.67Co _0.2B _0.08Ga _0.05) _5.6The relation curve that changes with heating-up temperature Deng the irreversible flux loss of magnet.

Fig. 8 (a) to (d) is Nd (Fe _0.72Co _0.2B _0.08) _5.6, Nd _0.8Dy _0.2(Fe _0.72Co _0.2B _0.08) _5.6, Nd (Fe _0.67Co _0.2B _0.08Al _0.05) _5.6And Nd (Fe _0.67Co _0.2B _0.08Ga _0.05) _5.6The relation curve that changes with heating-up temperature Deng the open loop magnetic flux of magnet.

Fig. 9 (a) to (d) is the Nd (Fe for preparing under various sintering temperatures _0.67-z-uCo _0.25B _0.08Ga ₂W _u) _5.6, Nd (Fe _0.67Co _0.25B _0.08) _5.6, Nd (Fe _0.65Co _0.25B _0.08Ga _0.02) _5.6And Nd (Fe _0.635Co _0.25B _0.08Ga _0.02W _0.015) _5.6Demagnetization curve Deng magnet.

The present invention that has a talk below limits the reason of the compositing range of each composition in the coupernick.

When adding cobalt in rare-earth iron-boron magnet, its Curie temperature is to have improved, but its crystal magnetic anisotropy constant decline, thereby coercive force is descended. But when adding simultaneously cobalt and gallium, can draw the higher magnet of Curie temperature, thereby improve coercive force. The element that adds aluminium and silicon and so in the Rare-earth Iron cobalt boron magnets is to improve coercive force, can add gallium but coercive force is improved to greatest extent. Although normally adopt heavy rare earth element such as terbium, dysprosium and holmium for improving coercive force, adopt gallium just can make the expensive heavy rare earth element of the eighteenth of the twenty (if any) as far as possible minimizing of use amount. Therefore add gallium or add simultaneously cobalt and gallium can remedy the low shortcoming that can cause poor heat stability of that Curie temperature of rare-earth iron-boron magnet, thereby draw coercive force and the Curie temperature more cheap magnet of the better cost of heat endurance that all is improved.

Take " X " expression the cobalt amount as 0～0.7. The cobalt amount surpasses at 0.7 o'clock, and it is low that residual magnetic flux density Br became. For fully improving Curie temperature Tc, the lower limit of cobalt is preferably 0.01, and for making the better balance cooperation of iHc and the magnetic properties such as Br and Tc, the upper limit of cobalt is preferably 0.4. Optimal cobalt amount is 0.05～0.25.

Adding gallium can make coercive force significantly improve. It seems that this raising be owing to improved in the magnet due to the Curie temperature of BCC phase. BCC has width at 100～5000 dusts around ndfeb magnet (Nd₂Fe ₁₄B) the polycrystalline phase of the body-centered cubic crystal structure in the principal phase. This BCC mutually again by rich neodymium phase (neodymium: 70～95 atomic percentages, all the other be iron) around. The Curie temperature of this BCC phase is lower than the temperature of 50 oersteds corresponding to the coercive force of magnet, greatly affects the temperature characterisitic of magnet. The adding gallium can improve the Curie temperature of BCC phase, effectively improves temperature characterisitic.

Take " Z " expression the gallium amount as 0.001～0.15. When the gallium amount less than 0.001 the time, to improving the basically not impact of magnet Curie temperature. On the other hand, when " Z " surpasses 0.15, saturated magnetization and Curie temperature are descended greatly, draw our undesirable permanent-magnet material. The gallium amount of comparatively ideal gallium amount is 0.002～0.10, and optimal gallium amount is 0.005～0.05.

When the boron amount of " Y " expression was less than 0.02, Curie temperature was low, can not get high-coercivity.On the other hand, when boron amount " Y " greater than 0.3 the time, saturation magnetization increases, and forms the undesirable phase of magnetic property.Therefore the boron amount should be 0.02～0.3." Y " comparatively ideal scope is 0.03～0.20.Optimal boron amount is 0.04～0.15.

When " A " less than 4 the time, saturation magnetization is low, when " A " surpasses 7.5, rich iron and cobalt occur mutually, thereby coercive force is descended greatly.Therefore " A " should be 4.0～7.5.Comparatively ideal " A " scope is 4.5～7.0.Optimal " A " scope is 5.0～6.8.

Permanent magnet of the present invention also can contain other element, and this element total usefulness " M " in following formula is represented:

R〔Fe _1-x-y-z-uCo _xB _yGa _zM _u〕 _A

R neodymium only wherein, or one or more rare earth elements of mainly forming by neodymium, praseodymium or cerium, their a part of available dysprosiums, terbium or holmium replace, M is one or more elements of choosing from niobium, tungsten, vanadium, tantalum or molybdenum, 0≤X≤0.7,0.02≤Y≤0.3,0.001≤Z≤0.15,0.001≤u≤0.1,4.0≤A≤7.5.

Adding niobium, tungsten, vanadium, tantalum or molybdenum is in order to prevent grain growth.These elements are 0.001～0.1 with the amount of " u " expression.When " u " less than 0.001 the time, can not obtain effect of sufficient, when " u " surpassed 0.1, saturation magnetization descended greatly, draws undesirable permanent magnet.

Add niobium to the Br(residual magnetic flux density) the minimizing effect do not resemble when adding gallium so by force, but iHc is slightly increased.Niobium is effective to improving corrosion resistance, so when the highly heat-resistant alloy may be exposed to higher temperature, niobium was the height effective additives.Less than 0.001 o'clock, can not play the effect that is enough to improve iHc with the niobium amount of " u " expression, simultaneously the corrosion resistance of coupernick is not high enough.On the other hand, when the niobium amount surpassed 0.1, Br and Curie temperature can descend significantly, and this is that we are undesirable.The comparatively ideal scope of niobium is 0.002≤Z≤0.04.

Add tungsten (w) and can improve temperature characterisitic greatly.When tungsten amount (" u ") surpassed 0.1, saturation magnetization and coercive force descended significantly.When " u " less than 0.001 the time, can not obtain effect of sufficient.Comparatively ideal tungsten amount is 0.002～0.04.

As for rare earth element " R ", can only use neodymium, or neodymium and such as praseodymium or cerium, or praseodymium adds the light rare earth element adapted of cerium and so on.When containing praseodymium and/or cerium, praseodymium desirable 0: 1～1: 0, cerium desirable 0: 1～0.3: 0.7 to the ratio of neodymium to the ratio of neodymium.

The also available dysprosium of neodymium replaces, and dysprosium has omited the effect that improves Curie temperature and coercive force iHc.Therefore add the thermal stability that dysprosium can improve permanent magnet of the present invention effectively.But can cause residual magnetic flux density Br to descend when dysprosium is excessive.Therefore dysprosium to the ratio of neodymium by former than should be 0.03: 0.97～0.4: 0.6.Comparatively ideal atomic ratio is 0.05～0.25.

Permanent magnet of the present invention can be produced with powder metallurgic method, quick quenching method or resin-bonding method.To introduce these methods below.

(1) powder metallurgic method

Coupernick system produces with arc-melting method or high frequency fusion method.The purity of raw material: rare earth element be 90% or more than, iron be 95% or more than, cobalt be 95% or more than, boron be 90% or more than, gallium be 95% or more than, M(niobium, tungsten, vanadium, tantalum, molybdenum) and (if any words) be 95% or more than.The boron raw material can be a ferroboron, and gallium material can be the iron gallium alloy.In addition, M(niobium, tungsten, vanadium, tantalum, molybdenum) raw material can be ferroniobium, ferrotungsten, ferrovanadium, iron tantalum alloy or ferromolybdenum, in view of ferroboron and iron gallium alloy contain the impurity of aluminium and silicon and so on inevitably, therefore can utilize the synergistic effect of the dvielement of gallium, aluminium and silicon to obtain high coercive force.

Crushing process can comprise to be pulverized and levigate operation.Pulverize availablely stamp, jaw crusher, brown mill, disk mill etc. carry out, grind then available aeropulverizer, vibration milling, ball mill etc. and carry out.Under any circumstance, crushing process is preferably in the nonoxidizing atmosphere and carries out, in case alloy oxidation.Final size is preferably 2～5 microns (FSSS).

The fine powder that draws is suppressed with mould in magnetic field.Make alloy have anisotropic performance, have any to be absolutely necessary, magnetic promptly to be pressed, its each C axis should equidirectional arrangement.Sintering be under 1050 ℃～1150 ℃ such as inert gases such as argon, helium in or carry out in the vacuum or in hydrogen.Heat treatment is to carry out under 400 ℃～1000 ℃ on the coupernick that sinters.

(2) quick quenching

Coupernick prepares in the same mode of powder metallurgic method (1).The alloy melt that draws is with mono-roller type or the quick quenching of double-roll type quenching device.That is, for example alloy with the high frequency fusing is ejected on the roller of high speed rotating by a nozzle, thereby makes its quick quenching.The sheet products that draws is heat-treated under 500～800 ℃.The material made from this quick quenching method can be used as three kinds of permanent magnets.

First) with disk mill etc. the sheet products that draws is crushed to 10～500 microns granularity.Powder is mixed with for example epoxy resin so that carry out molding, or mix to carry out injection moulding with nylon resin.For improving the bonding force of alloy powder and resin, before blending, can in the alloy powder, add suitable coupling agent.The magnet that draws is isotropic.

Second) with hot press or isobaric hot press (HIP) compacting sheet products, to produce loose shape isotropic magnet.The magnet that so prepares is isotropic.

Third) with the in addition upsetting of loose isotropic magnet of obtaining in above-mentioned (second), make it flat.Plastic deformation makes magnet have anisotropic properties, and promptly its C axis is arranged by same direction.The magnet that so prepares is anisotropic.

(3) resin-bonding method

Raw material can be the object that sintering that the rare earth iron cobalt boron gallium alloy, pulverizing and the above-mentioned alloy of sintering that obtain in above-mentioned (1) draw is crossed.Draw the bulk products that quick quenching thin slice or hot pressing or upsetting thin slice draw in above-mentioned (2).With jaw crusher, brown mill, disk mill etc. these bulk products are ground into 30～500 microns granularity.With fine powder and the mixed with resin that draws, to molding or injection molded.In moulding process, apply magnetic field and can draw the anisotropic magnet that the C axis is got same direction arrangement.

Be described in further detail content of the present invention by following all examples now.

In all examples, used raw material is the neodymium of purity 99.9%, the iron of purity 99.9%, the cobalt of purity 99.9%, the boron of purity 99.5%, the gallium of purity 99.9999%, the tungsten of the niobium of purity 99.9% and purity 99.9%, all other employed elements, its purity all be 99.9% or more than.

Example 1

Be equipped with it with the arc-melting legal system and consist of Nd (Fe _0.70Co _0.2B _0.07M _0.03) _6.5The various alloys of (M=boron, aluminium, silicon, phosphorus, titanium, vanadium, chromium, manganese, nickel, copper, gallium, germanium, chromium, niobium, molybdenum, silver, indium, antimony, tungsten).The ingot blank that draws is carried out coarse crushing with stampping with disk mill, be screened into, grind with aeropulverizer than after the also thin granularity of 32 orders.Crushing medium is a nitrogen, so the granularity of drawing (FSSS) is 3.5 microns a fine powder.The powder that draws is suppressed in the magnetic field of 15 kilo-oersteds, and the direction in magnetic field is perpendicular to the direction of compacting.Pressing pressure is 2 tons/square centimeter.With sintering in the vacuum of green object under 1090 ℃ that draws 2 hours.After the quenching, under 500～900 ℃, heat-treat.The result as shown in Table 1.

In 19 elements " M " of being studied, have only gallium can obtain to surpass the iHc of 10 kilo-oersteds.This shows that gallium is effective especially to improving coercive force.By the way, though add aluminium coercive force has been improved, coercive force has only 8.5 kilo-oersteds.

Example 2

By the same mode of example 1 to the alloy with following composition pulverize, levigate, sintering and heat treatment.

Nd〔Fe _0.9-xCo _xB _0.07Ga _0.03〕 _5.8（X＝0，0.05，0.1，0.15，0.2，0.25）;

Nd (Fe _0.93-xCo _xB _0.07) _5.8(X=0,0.05,0.1,0.15,0.2,0.25); With

Nd _0.9Dy _0.1(Fe _0.93-xCo _xB _0.07) _5.8X=0,0.05,0.1,0.15,0.2,0.25); With

The magnet that draws is measured with regard to its magnetic property, and the result is shown in table two, table three and table four.

Table two

Nd (Fe _0.9-xCo _xB _0.07Ga _0.03) _5.8The magnetic property of magnet

X 0 0.05 0.1 0.15 0.2 0.25

Magnetic property

4 π Ir(kilogauss) 12.6 12.55 12.43 12.31 12.2 12.09

The iHc(kilo-oersted) 20.6 19.6 18.3 17.9 17.8 16.5

(BH) maximum 37.0 36.2 35.6 35.1 34.3 33.2

(mega gaussorersted)

Table three

Nd (Fe _0.93-xCo _xB _0.07) _5.8The magnetic property of magnet

X 0 0.05 0.1 0.15 0.2 0.25

Magnetic property

4 π Ir(kilogauss) 13.4 13.32 13.21 13.09 13.0 12.88

The iHc(kilo-oersted) 9.0 8.8 8.3 8.0 7.5 7.1

(BH) maximum 42.1 41.5 41.1 40.8 39.7 38.8

(mega gaussorersted)

Table four

Nd _0.9Dy _0.1(Fe _0.93-xCo _xB _0.07) _5.8The magnetic property of magnet

X 0 0.05 0.1 0.15 0.2 0.25

Magnetic property

4 π Ir(kilogauss) 12.62 12.51 12.38 12.31 12.19 12.11

The iHc(kilo-oersted) 15.6 15.0 14.1 13.4 12.3 11.6

(BH) maximum 38.2 37.5 36.2 35.8 35.0 34.3

(mega gaussorersted)

The cobalt amount is respectively each sample of 0 and 0.2 and heated at various temperatures 30 minutes, measure with regard to the variation of its open loop magnetic flux (irreversible flux loss) then, to understand their thermal stability.The sample of tested person is that those are processed into and make its unit permeance be-2 sample.Sample is magnetized under 25 kilo-oersted magnetic field intensitys, measure its magnetic flux down for the first time at 25 ℃.Sample is heated to 80 ℃, is cooled to 25 ℃ then, measure magnetic flux once more.So just determined the irreversible flux loss under 80 ℃.Progressively heating-up temperature is risen to 200 ℃, each step promotes 20 ℃, obtains at each temperature irreversible flux loss by same mode.The result as depicted in figs. 1 and 2.From here as can be seen, add the coercive force that gallium has improved magnet, thereby improved their thermal stability greatly.

Example 3

By the same mode of example 1 to each magnet with following composition pulverize, grind, sintering and heat treatment:

Nd (Fe _0.7Co _0.2B _0.08Ga _0.02) _A(A=5.6,5.8,6.0,6.2,6.4,6.6) and

Nd〔Fe _0.92B _0.08〕 _A〔A＝5.6，5.6，6.0，6.2，6.4，6.6〕

Each magnet of so preparing is measured with regard to its magnetic property.The results are shown in table five and table six.

Table five

Nd (Fe _0.7Co _0.2B _0.08Ga _0.02) _AThe magnetic property of magnet

A 5.6 5.8 6.0 6.2 6.4 6.6

Magnetic property

4 π Ir(kilogauss) 12.25 12.32 12.39 12.48 12.56 12.7

The iHc(kilo-oersted) 15.4 15.1 15.6 14.2 13.1 12.0

(BH) maximum 35.8 36.1 36.0 36.5 36.9 37.1

(mega gaussorersted)

Table six

Nd (Fe _0.92B _0.08) _AThe magnetic property of magnet

A 5.6 5.8 6.0 6.2 6.4 6.6

Magnetic property

4 π Ir(kilogauss) 13.04 13.2 13.4 13.6 13.7 13.8

The iHc(kilo-oersted) 10.0 9.3 9.0 000

(BH) maximum 40.2 41.3 42.6 000

(mega gaussorersted)

As A=6.2 or when above, the iHc of neodymium iron boron ternary alloy three-partalloy and (BH) maximum are almost 0.Even but when A was 6.6, if add cobalt and gallium, then coercive force can be high, thereby magnetic property is good.Can explain like this that theoretically in the neodymium iron boron ternary alloy three-partalloy, when A is 6.2 or when above, the oxidation of neodymium makes that the rich neodymium as liquid phase reduces mutually in sintering process, thereby can not obtain coercive force.On the other hand, when adding cobalt and gallium simultaneously, gallium has replaced the verified neodymium that is oxidized as liquid phase, thereby makes it have high coercive force.

Example 4

The alloy of getting everything ready and forming with the arc-melting legal system: Nd (Fe by following _0.82Co _0.1B _0.07Ga _0.01) _6.5And Nd (Fe _0.93B _0.07) _6.5With single-roller method with the alloy that draws quenching fast from their melt.With the tablet that draws 700 ℃ of following heat treatments 1 hour.The sample that will so prepare with disk mill is ground into about 100 microns.Each the meal material formed that draws is divided into two groups: (first) wherein one group with the epoxy resin blending, molding then, (second) another group is then carried out hot pressing.The magnetic property of each magnet that so draws is shown in table seven.

Table seven

The magnetic property of all magnet that quick quenching method prepares

Nd〔Fe _0.82Co _0.1B _0.07Ga _0.01） _6.5Nd（Fe _0.93B _0.07） _6.5

Magnetic property (first) (second) (first) (second)

4 π Ir(kilogauss) 6.1 8.4 6.3 8.8

The iHc(kilo-oersted) 21.6 20.1 14.6 12.3

(BH) maximum 7.1 13.2 7.3 13.6

(mega gaussorersted)

Irreversible flux loss * 1.3 1.8 4.3 5.1

Annotate *: in 100 ℃ of heating irreversible flux loss after 0.5 hour

(first) bonded type magnet

(second) heat pressing type magnet

From above-mentioned data as can be known, when adding cobalt and gallium simultaneously, iHc up to 20 kilo-oersteds or more than, thereby draw the magnet of good thermal stability.

Example 5

The alloy of getting everything ready and forming with the arc-melting legal system: Nd (Fe by following _0.82Co _0.1B _0.07Ga _0.01) _5.4Fast the alloy that draws is carried out quenching from its melt with single-roller method.With isobaric hot press sample is suppressed, made it flat by upsetting again.The magnet that draws has following magnetic property: 4 π Ir=11.8 kilogauss, iHc=13.0 kilo-oersted, (BH) maximum=32.3 mega gaussorersteds.

Example 6

The alloy of getting everything ready and forming with the arc-melting legal system: Nd (Fe by following _0.82Co _0.1B _0.07Ga _0.01) _5.4And Nd (Fe _0.92B _0.08) _5.4The alloy that draws is processed with two kinds of methods: (first) one of them be crushed to 50 microns or below, another carries out quenching from its melt fast with single-roller method (second), with the sheet products that draws through isobaric hot pressing (HIP), carry out upsetting again and make it flat, be crushed to then 50 microns or below.These powders are mixed with epoxy resin, in magnetic field, be made into magnet then.The magnet that draws, its magnetic property is shown in table eight.Should be noted that the coercive force of neodymium iron boron ternary alloy three-partalloy is extremely low, and the magnet that contains cobalt and gallium two elements have enough coercive forces.

Table eight

The magnetic property of bonded type magnet

Nd（Fe _0.82Co _0.1B _0.07Ga _0.01） _5.4Nd（Fe _0.92B _0.08） _5.4

Magnetic property (first) (second) (first) (second)

4 π Ir(kilogauss) 8.2 9.3 8.6 9.6

The iHc(kilo-oersted) 5.0 7.6 0.8 2.3

(BH) maximum 13 18 3 10

(mega gaussorersted)

Annotate: (first) ingot blank → pulverizing → resin-bonding

(second) ingot blank → quenching → HIP → upsetting → pulverizing → resin fusion fast.

Example 7

The alloy that will have following composition with the high frequency fusion method is made ingot blank:

（Nd _0.8Dy _0.2）〔Fe _0.835Co _0.06B _0.08Nb _0.015Ga _0.01〕 _5.5。The alloy ingot blank that draws is carried out coarse crushing with stampping with disk mill, and it is broken to carry out fine powder then in as the nitrogen of crushing medium, is 3.5 microns fine powder material to produce granularity (FSSS).This fine powder material is suppressed in 15 kilo-oersted magnetic fields, and the direction in magnetic field is perpendicular to the direction of compacting.Neutralizing pressure is 2 tons/square centimeter.With sintering in the vacuum of green object under 1100 ℃ that draws 2 hours.The alloy that a series of sintering that draw are crossed is 900 ℃ of heating 2 hours down, slowly is cooled to room temperature with 1.5 ℃/minute speed then.

Under all temps between 540 ℃ and 460 ℃, anneal after the cooling.Measure every magnetic property of each heat treated magnet, it the results are shown in table nine.

Table nine

Br bHc iHc (BH) maximum

Annealing temperature (℃) (Gauss) (oersted) (oersted) (mega gaussorersted)

540 10400 10000 26500 26.0

560 10450 10010 26500 26.2

580 10400 10000 26400 26.0

600 10450 10100 26400 26.4

620 10400 10100 26200 26.0

640 10400 10100 25200 26.1

These magnet make its unit permeance Pc=-2 with their processing after overheated demagnetization, magnetize under 25 kilo-oersteds again.Their each increases between 180 ℃ and 280 ℃ are heated for 20 ℃, last 1 hour.Measure the irreversible flux loss under each heating-up temperature, it the results are shown in table ten.

Table ten

Irreversible flux loss (%, Pc=-2)

Annealing temperature (℃) 180 200 220 240 260 280

540 0.8 1.0 1.3 1.9 4.0 25.0

560 0.8 1.0 1.2 1.8 3.8 22.5

580 0.9 1.1 1.3 1.8 3.2 21.6

600 0.9 1.1 1.2 2.0 4.2 19.3

620 0.9 1.1 1.2 1.8 7.6 22.0

640 0.8 1.0 1.2 2.2 4.3 25.4

As can be seen from Table 10, even 260 ℃ of heating down, irreversible flux loss also is 5%, and this illustrates this all magnet Heat stability is good.

For comparison purpose, prepared (Nd by above-mentioned the same manner _0.8Dy _0.2) (Fe _0.86Co _0.06B _0.08) _5.5Alloy.Annealing temperature is 600 ℃.The magnet that draws, its magnetic property is as follows: Br is near 11200 Gausses, and bHC is near 10700 oersteds, and iHc is near 24000 oersteds, and (BH) is maximum near 29.8 mega gaussorersteds.When Pc=-2, the irreversible flux loss that produces because of heating is: when heating 180 ℃ is 1.0%, is 1.8% when heating 200 ℃, is 5.7% when heating 220 ℃, is 23.0% when heating 240 ℃.

Therefore obviously, when adding niobium and gallium simultaneously, thermal endurance increases about 40 ℃.

Example 8

By the same mode of example 7 with three kinds of alloy meltings with following expression formula, pulverize, make goods:

(Nd _0.8Dy _0.2) (Fe _0.92-xCo _xB _0.08) _5.5, X=0.06～0.12 wherein,

(Nd _0.8Dy _0.2) (Fe _0.905-xCo _xB _0.08Nb _0.015) _5.5, X=0.06～0.12 wherein,

(Nd _0.8Dy _0.2) (Fe _0.895-xCo _xB _0.08Nb _0.015Ga _0.01) _5.5, X=0.06～0.12 wherein,

With sintering in the vacuum of each green object under 1090 ℃ that draws 1 hour, then 900 ℃ of following heat treatments 2 hours, then at 1 ℃/minute speed cool to room temperature.To heat 1 hour cooling fast in water then during annealing in its argon gas stream under 600 ℃ once more.Measure the magnetic property of each sample, it the results are shown in table ten one (first)～(third).

Table ten one (first)

〔Nd _0.8Dy _0.2〕〔Fe _0.92-xCo _xB _0.08〕 _5.5

Br bHc iHc (BH) maximum

X (Gauss) (oersted) (oersted) (mega gaussorersted)

0.06 11000 10500 24000 30.0

0.08 11050 10500 20000 30.1

0.10 11050 10450 17000 30.5

0.12 11000 10500 15000 30.0

Table ten one (second)

〔Nd _0.8Dy _0.2〕〔Fe _0.905-xCo _xB _0.08Nb _0.015〕 _5.5

Br bHc iHc (BH) maximum

X (Gauss) (oersted) (oersted) (mega gaussorersted)

0.06 10800 10400 22400 28.0

0.08 10900 10500 18200 28.8

0.10 10800 10400 16000 28.0

0.12 10900 10400 15100 28.2

Table ten one (the third)

〔Nd _0.8Dy _0.2〕〔Fe _0.895-xCo _xB _0.08Nb _0.015Ga _0.01〕 _5.5

Br bHc iHc (BH) maximum

X (Gauss) (oersted) (oersted) (mega gaussorersted)

0.06 10450 10100 26400 26.4

0.08 10500 10200 25300 26.6

0.10 10550 10200 24000 26.7

0.12 10500 10200 22700 26.7

Also listed the irreversible flux loss that heating causes in table ten two (first)～(third).Any in these three kinds of alloys, cobalt content all can make iHc reduce when increasing and (BH) maximum is constant haply.Irreversible magnetic flux consumption becomes big with the increase of cobalt content.Thermal endurance is the highest when the cobalt amount is 0.06.Relatively these three kinds of alloys as can be seen, both having contained gallium, also to contain the alloy thermal endurance of niobium the highest.

Table ten two (first)

〔Nd _0.8DY _0.2〕〔Fe _0.92-xCo _xB _0.08〕 _5.5

Irreversible flux loss (%, Pc=-2)

X 160℃ 200℃ 220℃

0.06 0.12 3.3 9.6

0.08 0.08 3.9 10.3

0.10 8.2 28.5 35.5

0.12 9.5 30.1 37.1

Table ten two (second)

〔Nd _0.8DY _0.2〕〔Fe _0.905-xCo _xB _0.08Nb _0.015〕 _5.5

Irreversible flux loss (%, Pc=-2)

x 160℃ 200℃ 240℃ 260℃

0.06 0.74 0.96 9.5 26.3

0.08 0.75 9.5 18.8 35.5

0.10 2.3 19.3 44.6 59.8

0.12 3.5 26.1 51.6 61.5

Table ten two (the third)

〔Nd _0.8DY _0.2〕〔Fe _0.895-xCo _xB _0.08Nb _0.015Ga _0.01〕 _5.5

Irreversible flux loss (%, Pc=-2)

x 180℃ 200℃ 240℃ 260℃ 280℃

0.06 0.94 1.1 2.0 4.2 19.3

0.08 0.76 0.97 1.7 8.0 21.6

0.10 0.74 0.92 1.6 5.2 18.7

0.12 0.70 0.94 3.4 12.4 24.4

Example 9

By example 7 same modes will have following expression formula various alloy meltings, pulverize and make magnet:

(Nd _0.8Dy _0.2) (Fe _0.86-uCo _0.06B _0.08Nb _u) _5.5, u=0～0.05 wherein.With sintering in the vacuum of green object under 1080 ℃ that draws 2 hours.The object that the sintering that draws is crossed heated 2 hours down at 900 ℃ again.Be cooled to room temperature with 2 ℃/minute cooling rate then.To heat 0.5 hour cooling fast in water then during annealing in their argon gas stream under 600 ℃ again.Measure the magnetic property of each sample, it the results are shown in table ten three.

Table ten three

〔Nd _0.8Dy _0.2〕〔Fe _0.86-uCo _0.06B _0.08Nb _u〕 _5.5

Br bHc iHc (BH) maximum

U (Gauss) (oersted) (oersted) (mega gaussorersted)

0 11050 10700 22500 29.5

0.003 11050 10700 23100 29.2

0.006 11050 10600 23800 29.0

0.009 10850 10500 24300 28.2

0.012 10850 10500 24700 28.4

0.015 10850 10500 25000 28.3

0.020 10700 10400 26200 27.4

0.030 10500 10000 28000 26.1

0.040 10300 9900 ＞28000 25.3

0.050 10150 9700 ＞28000 24.0

Obviously add niobium and can make Br and (BH) maximum decline, iHc is increased.As can be seen, irreversible flux loss reduces with the increase of iHc when heating down for 220 ℃ from table ten four.

Table ten four

〔Nd _0.8DY _0.2〕〔Fe _0.86-uCo _0.06B _0.08Nb _u〕 _5.5

U the irreversible magnetic energy loss in 220 ℃ of whens heating (%, Pc=-2)

0 10.1

0.003 8.7

0.006 6.3

0.009 5.0

0.012 4.6

0.015 3.1

0.020 2.5

0.030 2.0

0.040 1.8

0.050 1.5

Example 10

The alloy that will have following expression formula by example 7 same modes:

(Nd _0.8Dy _0.2) (Fe _0.8-zCo _0.06B _0.08Ga _z) _5.5Melt, pulverize and make magnet.After the sintering, each is 900 ℃ of down heating 2 hours with them, is cooled to room temperature with 1.5 ℃/minute cooling rate then, annealing 1 hour in the argon gas stream 580 ℃ under again, quick quenching in water then.The magnetic property of each magnet that draws is shown in table ten five, and their irreversible flux loss when heating down for 220 ℃ are shown in table ten six.

Table ten five

〔Nd _0.8Dy _0.2〕〔Fe _0.86-zCo _0.06B _0.08Ga _z〕 _5.5

Br bHc iHc (BH) maximum

Z (Gauss) (oersted) (oersted) (mega gaussorersted)

0 11050 10700 22500 29.5

0.002 10900 10600 23500 28.8

0.01 10600 10200 26500 27.2

0.03 10300 10000 ＞28000 25.6

0.07 9500 9200 ＞28000 21.7

0.10 8900 8600 ＞28000 18.9

0.12 8500 8200 ＞28000 17.0

0.15 8000 7800 ＞28000 15.3

Table ten six

〔Nd _0.8Dy _0.2〕〔Fe _0.86-zCo _0.06B _0.08Ga _z〕 _5.5

Z the irreversible flux loss in 220 ℃ of whens heating (%, Pc=-2)

0 10.1

0.002 7.5

0.01 2.7

0.03 0.7

0.07 0.5

0.10 0.3

0.12 0.1

0.15 0.1

As can be seen, add gallium Br and (BH) maximum are descended significantly, iHc is increased considerably, thereby improve the thermal endurance (thermal stability) of each magnet.

Example 11

By example 10 same modes will have following chemical formula alloy melting, pulverize and make magnet: (Nd _0.9Dy _0.1) (Fe _0.845-zCo _0.06B _0.08Nb _0.015Ga _z) _5.5, Z=0～0.06 wherein.The magnetic property of measuring is shown in table ten seven, is shown in table ten eight in the irreversible flux loss of 200 ℃ of heating.

Table ten seven

〔Nd _0.9Dy _0.1〕〔Fe _0.845-zCo _0.06B _0.08Nb _0.015Ga _z〕 _5.5

Br Hc iHc 〔BH〕

Z (Gauss) (oersted) (oersted) maximum (mega gaussorersted)

0 11850 11550 15200 34.1

0.01 11400 11000 19800 31.6

0.02 11100 10800 24900 29.7

0.03 11100 10600 28000 29.1

0.04 10800 10300 ＞28000 28.0

0.06 10550 10100 ＞28000 26.9

Table ten eight

〔Nd _0.9Dy _0.1〕〔Fe _0.845-zCo _0.06B _0.08Nb _0.015Ga _z〕 _5.5

The irreversible flux loss (%, Pc=-2) of Z when 200 ℃ of heating

0 38.1

0.01 20.3

0.02 4.5

0.03 1.8

0.04 1.2

0.05 0.7

As can be seen, promptly use a spot of Dy to replace neodymium, add the thermal stability that gallium also can improve magnet.

Example 12

Be equipped with and by the following alloy of forming with the arc-melting legal system: Nd (Fe _0.86Co _0.06B _0.08) _5.6, Nd (Fe _0.84Co _0.06B _0.08Ga _0.02) _5.6And Nd (Fe _0.825Co _0.06B _0.08Ga _0.02W _0.015) _5.6The ingot blank that draws is carried out coarse crushing with stampping with disk mill, cross be sieved to than 32 orders also thin after, levigate with aeropulverizer.Crushing medium adopts nitrogen, so draw the fine powder material of 3.5 micron granularities (FSSS).With the powder press forming in the magnetic field of 15 kilo-oersteds that draws, the direction in magnetic field is perpendicular to the direction of compacting.Pressing pressure is 2 tons/square centimeter.With sintering in the vacuum of green object under 1080 ℃ of Austria that draws 2 hours.After the quenching, heat-treated under 500～900 ℃ 1 hour, it the results are shown in table ten nine.

Table ten nine

The magnetic property of neodymium iron cobalt boron gallium tungsten magnet

(thousand (BH) maximum (million for 4 π Ir iHc

Form (kilogauss) oersted) Gauss's oersted)

Nd〔Fe _0.86Co _0.06B _0.08〕 _5.613.0 11.2 40.3

Nd〔Fe _0.84Co _0.06B _0.08Ga _0.02〕 _5.612.4 17.3 36.4

Nd〔Fe _0.825Co _0.06B _0.08Ga _0.02W _0.015〕 _5.612.1 18.7 35.3

Each sample was heated 30 minutes at various temperatures, measure with regard to the variation of open loop magnetic flux then, to understand its thermal stability.To be those make its unit permeance (PC) be-2 sample its processing with the sample of tested person.The results are shown in Fig. 3.Can draw the high magnet of thermal stability when as can be seen from Figure 3, adding cobalt, gallium and tungsten simultaneously.

Example 13

By example 12 same modes the alloy with following composition is pulverized, is ground and sintering:

Nd〔Fe _0.85-2Co _0.06B _0.08Ga _zW _0.01〕 _5.4〔Z＝0，0.01，0.02，0.03，0.04，0.05〕。

The magnet that draws, table two that its magnetic is shown in ten.

Measure Nd (Fe by example 12 same modes _0.85-zCo _0.06B _0.08Ga _zW _0.01) _5.4The thermal stability of (Z=0,0.02,0.04) sample, it the results are shown in Fig. 4.

Table two ten

Nd (Fe _0.85-zCo _0.06B _0.08Ga _zW _0.01) _5.4The magnetic property of magnet

Z 4 π Ir(kilogauss) iHc (kilo-oersted) (BH) maximum (mega gaussorersted)

0 12.6 12.5 37.8

0.01 12.32 15.2 35.8

0.02 12.06 17.4 34.7

0.03 11.77 18.5 33.0

0.04 11.52 19.7 31.7

0.05 11.29 21.0 29.3

Example 14

The alloy of getting everything ready and forming with the arc-melting legal system by following; Nd (Fe _0.825Co _0.06B _0.08Ga _0.02W _0.015) _6.0With single-roller method with the alloy that draws from the quick quenching of its melt.By following three kinds of methods the sheet products that draws is made loose shape:

(first) is 500～700 ℃ of following heat treatments, with epoxy resin blending, molding then.

(second) is 500～700 ℃ of following heat treatments, hot pressing then.

(the third) carry out isobaric hot pressing, upsetting makes it flat then.

The magnetic property of the magnet that draws is shown in table two 11.

Table two 11

Nd (Fe _0.825Co _0.06B _0.08Ga _0.02W _0.015) _6.0The magnetic property of magnet

Method 4 π Ir (kilogauss) iHc (kilo-oersted) (BH) maximum (mega gaussorersted)

(first) 6.0 22.6 7.1

(second) 8.0 20.2 12.6

(the third) 12.4 15.9 36.0

Measure the thermal stability of each sample by example 12 same modes, it the results are shown in Fig. 5.

Example 15

The alloy of getting everything ready and forming with the arc-melting legal system: Nd (Fe by following _0.85Co _0.04B _0.08Ga _0.02W _0.01) _6.1With single-roller method with the alloy that draws from the quick quenching of its melt.With the sample that isobaric hot pressing compacting is so prepared, upsetting makes it flat then.This bulk sample is crushed to less than 80 microns, and blending is shaped in magnetic field then with epoxy resin.The magnet that draws has following magnetic property: 4 π Ir=8.6 kilogauss, iHc=13.2 kilo-oersted, (BH) maximum=16.0 mega gaussorersteds.

Example 16

Being equipped with its composition formula with the arc-melting legal system is Nd _1-αDy _α(Fe _0.72Co _0.2B _0.08) _5.6(α=0,0.04,0.08,0.12,0.16,0.2), Nd (Fe _0.72-zCo _0.2B _0.08Al _z) _5.6(Z=0,0.01,0.02,0.03,0.04,0.05) and Nd (Fe _0.72-zCo _0.2B _0.08Ga _z) _5.6The alloy of (Z=0,0.01,0.02,0.03,0.04,0.05).The ingot blank that draws is carried out coarse crushing with stampping with disk mill, cross be sieved to than 32 orders thinner after, levigate with aeropulverizer.Crushing medium adopts nitrogen, so draw the fine powder material that granularity is 3.5 microns (FSSS).With the powder press forming in the magnetic field of 15 kilo-oersteds that draws, the direction in magnetic field is perpendicular to the direction of compacting.Pressing pressure is 1.5 tons/square centimeter.With sintering in the vacuum of green object under 1040 ℃ that draws 2 hours.After the quenching,, the results are shown in Fig. 6 600～700 ℃ of following heat treatments 1 hour.The magnet that contains gallium is than the magnet coercive force height that contains dysprosium or aluminium, and the fall of 4 π Ir and (BH) maximum is also little.

To consist of Nd (Fe _0.72Co _0.2B _0.08) _5.6, Nd _0.8Dy _0.2(Fe _0.72Co _0.2B _0.08) _5.6, Nd (Fe _0.67Co _0.2B _0.08Al _0.05) _5.6And Nd (Fe _0.67Co _0.2B _0.08Ga _0.05) _5.6The processing of all magnet, make its shape with unit permeance Pc=-2, after magnetization, heated at various temperatures 30 minutes, measure the variation of its open loop magnetic flux then, to understand their thermal stability.The result as shown in Figure 7.As can be seen from the figure, irreversible flux loss is relevant with coercive force with variation of temperature, and adds the magnet that gallium can be produced Heat stability is good, for example, the irreversible flux loss under 160 ℃ be 5% or below.

Example 17

(first) Nd (Fe from example 16 preparations _0.72Co _0.2B _0.08) _5.6, (second) Nd _0.8Dy _0.2(Fe _0.72Co _0.2B _0.08) _5.6, (third) Nd (Fe _0.67Co _0.2B _0.08Al _0.05) _5.6(fourth) Nd (Fe _0.67Co _0.2B _0.08Ga _0.05) _5.6Get some millimeters fritter on each limit of magnet, after magnetization, measure with the oscillatory type magnetometer with variation of temperature with regard to their magnetic flux.Mensuration is to carry out under the situation in magnetic field not having.The results are shown in Fig. 8.Magnetic flux has two flex points with variation of temperature, and a flex point is at the low temperature side corresponding to BCC phase Curie temperature, and another flex point is at the high temperature side corresponding to the principal phase Curie temperature.The magnet that contains gallium is lower than the Curie temperature of not additivated magnet in principal phase.On the other hand, aspect the Curie temperature of BCC phase, the former is than latter height.But add aluminium principal phase is descended greatly with BCC Curie temperature mutually, make thermal stability reach our undesirable degree.

Example 18

By the same mode of example 16 to the alloy with following composition pulverize, levigate, sintering and heat treatment:

Nd〔Fe _0.67Co _0.25B _0.08〕 _5.6

Nd (Fe _0.65Co _0.25B _0.08Ga _0.02) _5.6With

Nd〔Fe _0.635Co _0.25B _0.08Ga _0.02W _0.015〕 _5.6。

Sintering temperature is respectively 1020 ℃, 1040 ℃, 1060 ℃ and 1080 ℃.Measure their magnetic property, the results are shown in Fig. 9 (second)～(third).Fig. 9 (first) has compared the demagnetization curve of all magnet that above-mentioned its composition formula can be summarized as follows: Nd (Fe _0.67-z-uCo _0.25B _0.08Ga _zW _u) _5.6, Z=0 or 0.02 wherein, u=0 or 0.015.As can be seen, under the situation of tungstenic not, sintering temperature is high more from Fig. 9 (second) and (third), and the perpendicularity of the magnet that draws is poor more, causes the low coarse grained growth of coercive force.On the other hand, adding under the situation of tungsten, shown in Fig. 9 (fourth), can not cause coarse grained growth when improving sintering temperature, thereby perpendicularity is being good.From Fig. 9 (first) as can be seen, add the coercive force that gallium and tungsten have improved magnet.

Example 19

To consist of Nd (Fe by example 16 same modes _0.69Co _0.2B _0.08Ga _0.02M _0.01) _5.6The alloy of (wherein M is vanadium, niobium, tantalum, molybdenum or tungsten) pulverizes, levigate, sintering and heat treatment.The magnetic property of all magnet that draws is shown in table two 12.

Table two 12

Nd(Fe _0.69Co _0.2B _0.08Ga _0.02M _0.01) _5.6(M: vanadium, niobium, tantalum, molybdenum, tungsten)

Magnetic property

(thousand (BH) maximum (million for 4 π Ir iHc

Form (kilogauss) oersted) Gauss's oersted)

Nd〔Fe _0.69Co _0.2B _0.08Ga _0.02V _0.01〕 _5.612.0 17.0 34.0

Nd〔Fe _0.69Co _0.2B _0.08Ga _0.02Nb _0.01〕 _5.612.0 16.0 33.9

Nd〔Fe _0.69Co _0.2B _0.08Ga _0.02Ta _0.01〕 _5.611.9 16.5 33.0

Nd〔Fe _0.69Co _0.2B _0.08Ga _0.02Mo _0.01〕 _5.612.1 15.0 34.9

Nd〔Fe _0.69Co _0.2B _0.08Ga _0.02W _0.01〕 _5.611.8 17.5 33.1

Example 20

To consist of (Nd by example 16 same modes _0.8Dy _0.2) (Fe _0.85-uCo _0.06B _0.08Ga _0.01Mo _u) _5.5The alloy of (wherein u=0～0.03) pulverizes, levigate, sintering and heat treatment.The magnet heating under 260 ℃ that draws is measured with regard to its magnetic property and irreversible flux loss (Pc=-2), be the results are shown in table two 13.

Table two 13

〔Nd _0.8Dy _0.2〕〔Fe _0.85-uCo _0.06B _0.08Ga _0.01Mo _u〕 _5.5

The maximum irreversible damage of Br bHc iHc (BH)

U (Gauss) (kilo-oersted) (kilo-oersted) (mega gaussorersted) consumes * (%)

0 11.0 10.5 26.0 29.4 16.7

0.005 10.8 10.3 27.0 28.2 9.0

0.010 10.6 10.2 28.5 27.0 4.0

0.015 10.5 10.0 29.0 26.0 2.1

0.02 10.3 9.8 ＞30.0 25.2 1.0

0.03 9.8 9.2 ＞30.0 22.8 0.9

Annotate the irreversible flux loss of *

Example 21

To consist of Nd (Fe by example 16 same modes _0.855-uCo _0.06B _0.075Ga _0.01V _u) _5.5(wherein u=0～0.02) pulverize, levigate, sintering and heat treatment.The all magnet heating under 160 ℃ that draws is measured with regard to its magnetic property and irreversible flux loss (Pc=-2), and it the results are shown in table two 14.

Table two 14

Nd〔Fe _0.855-uCo _0.06B _0.075Ga _0.01V _u〕 _5.5

The maximum irreversible damage of Br bHc iHc (BH)

U (Gauss) (kilo-oersted) (kilo-oersted) (mega gaussorersted) consumes * (%)

0 11.9 11.6 17.9 34.1 7.6

0.005 11.7 11.2 18.2 33.2 6.2

0.01 11.6 11.0 18.3 32.4 7.9

0.015 11.5 10.9 19.2 31.9 4.2

0.020 11.4 10.8 20.5 31.2 2.1

Annotate: the irreversible flux loss of *

Example 22

To consist of (Nd by example 16 same modes _0.9Dy _0.1) (Fe _0.85-uCo _0.06B _0.08Ga _0.01Ta _u) _5.5The alloy of (wherein u=0～0.03) pulverizes, levigate, sintering and heat treatment.The all magnet that draws is heated (Pc=-2) down with regard to its magnetic property and irreversible flux loss (Pc=-2) at 160 ℃, the results are shown in table two 15.

Table two 15

〔Nd _0.9Dy _0.1〕〔Fe _0.85-uCo _0.06B _0.08Ga _0.01Ta _u〕 _5.5

The maximum irreversible damage of Br bHc iHc (BH)

U (Gauss) (kilo-oersted) (kilo-oersted) (mega gaussorersted) consumes * (%)

0 11.8 11.3 16.5 33.5 8.2

0.005 11.6 11.1 17.5 32.4 4.1

0.010 11.4 10.9 18.9 31.5 3.7

0.015 11.3 10.9 19.5 30.7 3.2

0.020 11.1 10.6 19.8 29.8 3.0

0.025 10.9 10.4 20.2 28.7 2.1

0.030 10.7 10.3 21.0 27.7 1.9

Annotate: the irreversible flux loss of *

As described in above all examples, add gallium in the ndfeb magnet or add cobalt simultaneously and gallium can improve the Curie temperature and the coercive force of magnet, thereby improve the thermal stability of magnet.In addition, adding one or more in M(niobium, tungsten, vanadium, tantalum, the molybdenum in the ndfeb magnet simultaneously) cobalt and gallium can further improve the Curie temperature and the coercive force of magnet.

The present invention introduces by above all examples, but should be pointed out that this all example does not provide constraints to the present invention, and any modification only otherwise break away from the scope of the invention of the appended every claim regulation of this specification can be carried out.

Claims

1, a kind of permanent magnet of good thermal stability is characterized in that, the one-tenth that the available basically following general expression of this permanent magnet is represented is grouped into: R[Fe _1-x-y-zCo _xB _yGa _z] A

Wherein R neodymium only, or one or more rare earth element of mainly forming by neodymium, praseodymium or cerium, 0≤X≤0.7,0.02≤Y≤0.3,0.001≤Z≤0.15,4.0≤A≤7.5.

2, according to the permanent magnet of the good thermal stability of claim 1, it is characterized in that R wherein is a neodymium, available praseodymium of the part of neodymium and/or cerium replace, 0.01≤X≤0.4,0.03≤Y≤0.2,0.002≤Z≤0.1, and 4.5≤A≤7.0.

3, a kind of permanent magnet of good thermal stability is characterized in that, this permanent magnet is grouped into by the one-tenth that available following general expression is represented basically: R (Fe _1-x-y-z-uCo _xB _yGa _zM _u) wherein R can be neodymium only, or one or more rare earth metals of mainly forming by neodymium, praseodymium or cerium, the available dysprosium of a part in these rare earth elements, terbium or holmium replace, M is one or more elements that are selected from niobium, tungsten, vanadium, tantalum and molybdenum, 0≤X≤0.7,0.02≤Y≤0.3,0.001≤Z≤0.15,0.001≤u≤0.1,4.0≤A≤7.5.

4, according to the permanent magnet of claim 3 good thermal stability, it is characterized in that 0.01≤X≤0.4,0.03≤X≤0.2,0.002≤Z≤0.1,0.002≤u≤0.04,4.5≤A≤7.0.

According to the permanent magnet of claim 3 good thermal stability, it is characterized in that 5, R mainly is made up of neodymium and dysprosium, neodymium is formed dysprosium, and neodymium is 0.97: 0.03 to 0.6: 0.4 to the atomic ratio of dysprosium.

6, according to the permanent magnet of claim 5 good thermal stability, it is characterized in that 0.01≤X≤0.4,0.03≤Y≤0.2,0.002≤Z≤0.1,0.002≤u≤0.04 and 4.5≤A≤7.0.

7, according to the permanent magnet of the good thermal stability of any one claim of claim 3～6, it is characterized in that M is a niobium.