CN101256859A

CN101256859A - Rare-earth alloy casting slice and method of producing the same

Info

Publication number: CN101256859A
Application number: CN 200710151801
Authority: CN
Inventors: 于敦波; 李红卫; 徐静; 李世鹏; 李宗安; 颜世宏; 胡权霞; 袁永强; 李扩社
Original assignee: Grirem Advanced Materials Co Ltd
Current assignee: Grirem Advanced Materials Co Ltd
Priority date: 2007-04-16
Filing date: 2007-09-17
Publication date: 2008-09-03
Anticipated expiration: 2027-09-17
Also published as: CN101256859B; JP4776653B2; JP2008264875A

Abstract

The invention relates to a rare earth alloy casting strip and the preparation method. The thickness of the alloy casting strip is uniform, at least the thicknesses of 80% alloy casting strips are in the scope of [mu-0.1 mm, mu+0.1 mm], sigma<2> <=0.011 mm<2>. Wherein, the my is the average thickness of the alloy casting strips and is in the scope of 0.1-1.0 mm; the sigma<2> is the variance of the thicknesses of the alloy casting strips and represents the dispersion degree of the thicknesses of the alloy casting strips. The composition of the alloy casting strip is R(Fe, M)B, wherein, R represents one or more rare earth elements in the 17 rare earth elements including Sc and Y, whose percentage content is 26.0-50.0 wt%, M is a transition element except Fe, that is one or more in Al, Ga, In, C,N, Si, Ge, Sn, Pb, Mg and Ca, the percentage content of M is 0-10.0%, the percentage content of B is 0-1.5%, and the rest is Fe and inevitable impurities. The preparation method is that: after melt, the constituents below of the rare earth alloy are thrown into alloy strips by a rotating water cooled metallic roller. The alloy casting strip can be made into a sintered rare earth permanent magnet with high performance.

Description

A kind of rare-earth alloy casting slice and preparation method thereof

Technical field

The invention belongs to rare earth material and make the field, relate to uniform rare-earth alloy casting slice of a kind of thickness and preparation method thereof.

Technical background

The NdFeB magnet plays important effect because excellent magnetism can be widely used in fields such as computer, information electronics, national defence in new and high technology and daily life.Along with miniaturization of devices and intellectuality, the application meeting of high-performance neodymium-iron-boron magnet is more and more wider.Magnet mainly is divided into casting ingot process and casting blade technolgy with the preparation technology of Nd Fe B alloys.Wherein traditional casting ingot process is because cooling speed is slow, in casting process, form α-Fe on the one hand easily, α-Fe has deformability and reduces alloy the crush efficiency when pulverizing, and influence composition fluctuation, particle size distribution, reduce magnet performance, cause the segregation of rich R phase in the Nd Fe B alloys microstructure on the other hand easily, cause rich R in ingot casting, to form local big aggregation, make rich R phase and R ₂T ₁₄B mixes inhomogeneous mutually.In order to address the above problem, the casting blade technolgy has been proposed.The appearance of casting blade technolgy is a major transformation of traditional casting ingot process, and in the casting blade technolgy, molten alloy being cast to forming thickness on the water cooled rolls of rotation is the alloy casting piece of 0.1～1.0mm.In casting cycle, molten alloy is by rapid cooling curing, suppressed separating out of α-Fe, and organize tiny, the fine dispersion of crystal grain, grain boundary area is big, because rich R spreads very thinly in crystal boundary, so rich R is uniformly dispersed, thereby improve the microstructure of foundry alloy in matrix, improve magnetic property.Therefore adopt Nd Fe B alloys casting sheet to prepare the inexorable trend that the high-performance magnet is the sintered NdFeB industry development.

Chinese patent ZL97111284.3 and U.S. Pat 6322637, US2002017340 disclose a kind of Nd Fe B alloys casting sheet and manufacture method thereof, this patent mainly comprises composition, tissue and the preparation method who casts sheet, and Chinese patent ZL02805097.5, ZL02800585.6 disclose the roughness on composition, tissue and the casting sheet surface thereof of Nd Fe B alloys casting sheet.U.S. Pat 5930582 discloses the preparation technology of Nd Fe B alloys casting sheet.Japan Patent JP05-222488, JP08-111307, JP09-170055, JP10-036949, JP2000-219942 and JP2004-143595 have reported composition, tissue and the preparation method of Nd Fe B alloys casting sheet, main contents comprise: R is 27.0～34.0wt%, and wherein R is one or more in the rare earth element; Rich neodymium spaced apart (being the width of main phase grain) is 3～15 μ m, principal phase Nd ₂Fe ₁₄The percentage by volume of B is at least 88%; Strap thickness is that 0.03～10mm preparation method is: the alloy liquation of mentioned component is cast on the running roller of rotation, forms the casting sheet after cooling off.But it is thickness evenness that above patent has all been ignored an important indicator of weighing the casting tablet quality, and the performance of the magnet of preparation is all low slightly.

The inventor is by discovering recently, and the thickness evenness of rare-earth iron-boron alloy casting sheet has considerable influence to microstructure, thereby influences the performance of sintered rare-earth permanent magnetic body.The uniform alloy casting piece of thickness has good microscopic structure, is fit to preparation high-performance rare-earth permanent-magnetic body, and it is as follows to influence mechanism:

(1) crystallite dimension almost spherical in the casting sheet does not exist sharp-pointed seamed edge and angle and protrudes the position, helps improving coercive force.Because often there is very big diffusing magnetic field in these positions, maximum diffusing magnetic field can reach 4 π Ms, and it can bring out the formation of magnetic reversal farmland, causes coercive force to reduce;

(2) Nd in the casting sheet ₂Fe ₁₄B crystal grain is surrounded by the rich rare earth phase thin layer of the about 2nm of a layer thickness, makes crystal grain and intergranule isolated each other, does not have magnetic exchange lotus root cooperation usefulness, helps improving coercive force;

(3) principal phase Nd in the casting sheet ₂Fe ₁₄The volume fraction of B is big; Tiny rich rare earth evenly distributes mutually, plays the liquid-phase sintering effect in sintering process, helps improving the density p of sintered magnet, thereby helps preparing the rare-earth sintering magnet of high remanent magnetism Br and high energy product (BH) max.

The inventor has invented evenly also controlled rare-earth alloy casting slice of a kind of thickness and preparation method thereof on the basis of original casting blade technolgy (Strip casting technology).In sintering rare-earth iron boron magnet preparation process, adopt this rare-earth alloy casting slice can obtain higher magnetic property.Being two kinds of Nd Fe B alloyses castings of 0.3mm, thickness evenness different A, B sheet with average thickness μ is example, and A is an alloy casting piece of the present invention, the variances sigma of its thickness ²Be 0.002, and B is the casting sheet of tradition casting blade technolgy preparation, variances sigma ²Be 0.02.Wherein in the A casting sheet as the column crystal of principal phase along the parallel growth of backheating flow path direction, homogeneous grain size; And the grain size of column crystal is even inadequately in the B casting sheet.In order to compare the quality of these two kinds of rare-earth alloy casting tablet qualities, adopt same process that A, B casting sheet is made Sintered NdFeB magnet simultaneously.The result shows: the maximum magnetic energy product (BH) of using the Sintered NdFeB magnet of A alloy casting piece preparation _MaxUp to 406kJ/m ³The maximum magnetic energy product (BH) that obtains with the B alloy casting piece _MaxOnly be 371kJ/m ³As seen, thickness evenness is an important indicator of rare-earth alloy casting tablet quality, adopts the Rare-Earth Magnetic of the different casting sheet preparation of thickness evenness to know from experience the bigger performance difference of existence.

Technology contents

The objective of the invention is to develop uniform rare-earth alloy casting slice of a kind of thickness and preparation method thereof, this alloy casting piece has uniform microstructure, adopts this alloy casting piece can prepare high performance rare-earth permanent magnet.

The invention provides a kind of rare-earth alloy casting slice, it is characterized in that:

The thickness distribution of (1) at least 80% alloy casting piece in the scope of [μ-0.1mm, μ+0.1mm], σ ²≤ 0.011mm ², wherein μ is the average thickness of alloy casting piece, scope is 0.1～1.0mm; σ ²Be the variance of alloy casting piece thickness, the degree of scatter of expression alloy casting piece thickness;

(2) principal phase Nd in the alloy ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is at least 80%, and the width of column crystal is 0.2～50.0 μ m, and length is 1.0～500 μ m.

Rare-earth alloy casting slice provided by the invention, it is characterized in that: the composition of alloy casting piece is R (Fe, M) B, R representative comprises one or more in 17 kinds of rare earth elements of Sc, Y, and percentage composition is 26.0～50.0wt%, and M is among the transition element except that Fe, Al, Ga, In, C, N, Si, Ge, Sn, Pb, Mg, the Ca one or more, percentage composition is 0～10.0wt%, B is a boron, and percentage composition is 0～1.5wt%, and surplus is iron and unavoidable impurities.

The preparation method of rare-earth alloy casting slice provided by the invention, it is characterized in that: with confected materials melting in crucible, then alloy liquid is cast on the water cooled rolls of rotation by the casting groove, by control alloy flow quantity, get rid of bandwidth (being that rare earth alloy liquid is cast to the width on the water cooled rolls of rotation), cast temperature and water cooled rolls rotating speed, form the uniform alloy casting piece of thickness.

The method for controlling thickness of alloy casting piece of the present invention comprises and forms stable alloy flow quantity, stable bandwidth, stable cast temperature and the stable water cooled rolls rotating speed of getting rid of, and with these four optimum organizations, obtains the uniform rare-earth alloy casting slice of thickness.Correspondingly, grain size in the alloy casting piece and microstructure are very even.The principle of thickness evenness control is: the major influence factors of alloy casting piece thickness is the alloy flow quantity, get rid of bandwidth, cast temperature and water cooled rolls rotating speed.At first, under equal conditions, the alloy flow quantity is big more, and the thickness of alloy casting piece is also big more; Getting rid of bandwidth increases, and the thickness of alloy casting piece is more little; Cast temperature is high more, and the thickness of alloy casting piece is more little; The rotating speed of water cooled rolls is big more, and the thickness of alloy casting piece is more little.Therefore, obtain the rare-earth alloy casting slice of thickness uniformity, alloy liquid need be cast on the water cooled rolls of rotation by the mode of casting groove with planar flows, strict then control alloy flow quantity, the size of getting rid of bandwidth, cast temperature and water cooled rolls rotating speed require these four parameters adjustable and can stablize control.

The thickness distribution of (1) at least 80% alloy casting piece in the scope of [μ-0.1mm, μ+0.1mm], σ ²≤ 0.011mm ², wherein μ is the average thickness of alloy casting piece, scope is 0.1～1.0mm; σ ²Be the variance of alloy casting piece thickness, the degree of scatter of expression alloy casting piece thickness.

The thickness distribution of (2) at least 90% alloy casting pieces in the scope of [μ-0.1mm, μ+0.1mm], σ ²≤ 0.01mm ²

The thickness distribution of (3) at least 95% alloy casting pieces in the scope of [μ-0.1mm, μ+0.1mm], σ ²≤ 0.008mm ²

The thickness distribution of (4) at least 80% alloy casting pieces in the scope of [μ-0.05mm, μ+0.05mm], σ ²≤ 0.008mm ²

The thickness distribution of (5) at least 90% alloy casting pieces in the scope of [μ-0.05mm, μ+0.05mm], σ ²≤ 0.006mm ²

(6) the average thickness μ of alloy casting piece is 0.1～1.0mm.

The preparation method of rare-earth alloy casting slice provided by the invention is characterized in that:

(1) mode of heating of molten alloy is a kind of in Medium frequency induction melting, high-frequency induction melting, electric arc melting, the resistance wire heating melting.

(2) alloy flow quantity size is adjustable and can stablize control in 100g/s～10000g/s scope.

(3) it is adjustable and can stablize control in 50mm～600mm scope to get rid of bandwidth.

(4) cast temperature is adjustable and can stablize control in 1300 ℃～1600 ℃ scopes.

(5) the water cooled rolls rotating speed is adjustable and can stablize control in 0.2m/s～5.0m/s scope.

(6) method for controlling thickness of alloy casting piece comprises and forms stable alloy flow quantity, stable bandwidth, stable cast temperature and the stable water cooled rolls rotating speed of getting rid of, and with these four optimum organizations, obtains the uniform rare-earth alloy casting slice of thickness.

Rare-earth alloy casting slice of the present invention, the method for measurement of its thickness is: get 5 points arbitrarily at the different parts of single rare-earth alloy casting slice, measure with micrometer caliper or vernier caliper, the mean value that records is the thickness of single alloy casting piece, is designated as X _iThe average thickness of middle rare earth alloy casting piece of the present invention

μ = \frac{1}{N} \cdot Σ_{i = 1}^{N} x_{i},

Variance

δ^{2} = \frac{1}{N} Σ_{i = 1}^{N} {(x_{i} - μ)}^{2},

Wherein N represents the sum of alloy casting piece, and N is the bigger the better, but considers efficient, and generally selecting N is 30～100, and related data involved in the present invention is all based on N=50.

A kind of rare-earth alloy casting slice that the present invention relates to, the control procedure of alloy casting piece thickness can form mechanism and explain with the liquid film of single-roller method.The abstract model of single-roller method alloy casting piece forming process is seen accompanying drawing 5.

In a single day alloy liquid solidifies on its surface with any some the contact promptly on the running roller, the solidification layer progressive additive, and solidified layer thickness has reached certain value y when it breaks away from molten bath _mThis moment Separation of Solid and Liquid, y _mBe the alloy casting piece thickness of final acquisition.If the length that the molten bath contacts with single roller is x _d, then the thermal equilibrium condition of liquid film process of setting is

α (T_{m} - T_{r}) \frac{x_{d}}{rω} = y_{m} (Δh + cΔ T_{m})

The interfacial heat transfer coefficient of α one running roller and alloy liquid in the formula;

T _mOne alloy liquid temp;

Δ T _mOne alloy liquid superheating ratio;

T _rOne running roller surface temperature;

ω one angular velocity of rotation;

The radius of R one running roller;

C one alloy mass thermal capacitance;

Δ h one latent heat of solidification.

X wherein _d/ (r ω) is setting time, and the computing formula of alloy casting piece thickness is

y_{m} = \frac{α (T_{m} - T_{r}) x_{d}}{rω (Δh + cΔ T_{m})}

From following formula as can be known, the major influence factors of alloy casting piece thickness is interfacial heat transfer coefficient α, running roller speed omega, the alloy liquid temp T of running roller and alloy liquid _m, alloy mass thermal capacitance c, latent heat of solidification Δ h.For the alloy of certain ingredients, the major influence factors of alloy casting piece thickness is interfacial heat transfer coefficient α, running roller speed omega and alloy liquid temp T _mIn the actual process, the factor that influences interfacial heat transfer coefficient α is more, wherein alloy flow quantity size and get rid of the bandwidth size α is had bigger influence.Therefore, the major influence factors of alloy casting piece thickness is the alloy flow quantity, gets rid of bandwidth, cast temperature and water cooled rolls rotating speed that the thickness evenness of alloy casting piece is mainly determined jointly by these four factors.

Advantage of the present invention is: in uneven thickness at common rare-earth alloy casting slice, microstructure is inhomogeneous, be difficult to obtain this problem of higher magnet performance, uniform rare-earth alloy casting slice of a kind of thickness and preparation method thereof has been proposed, it is characterized in that: with confected materials melting in crucible, then alloy liquid is cast on the water cooled rolls of rotation, by controlling the alloy flow quantity, getting rid of bandwidth, cast temperature and water cooled rolls rotating speed, form the uniform alloy casting piece of thickness.The method for controlling thickness of alloy casting piece comprises and forms stable alloy flow quantity, stable bandwidth, stable cast temperature and the stable water cooled rolls rotating speed of getting rid of, and with these four optimum organizations, obtains the uniform rare-earth alloy casting slice of thickness.Rare-earth alloy casting slice of the present invention possesses uniform microstructure, is fit to preparation high-performance rare-earth iron boron magnet.

Description of drawings

Fig. 1 is the preparation schematic diagram of rare-earth alloy casting slice of the present invention.

Among the figure, 1 is melting kettle, and 2 are the casting groove, and 3 is alloy casting piece, and 4 is running roller, and 5 is the alloy casting piece gatherer.

Fig. 2 is the metallograph of the rare-earth alloy casting slice of the embodiment of the invention 1, along the cross section of thickness direction, amplifies 100 times.

Fig. 3 is the metallograph of the rare-earth alloy casting slice of the embodiment of the invention 1, along the cross section of thickness direction, amplifies 200 times.

Fig. 4 is the metallograph of the rare-earth alloy casting slice of the embodiment of the invention 1, along the cross section of thickness direction, amplifies 500 times.

As can be seen, the cross section along thickness direction in the rare-earth alloy casting slice of the present invention almost all is made of column crystal from Fig. 2～Fig. 4, principal phase Nd in the casting sheet ₂Fe ₁₄B crystal grain is the approximate column crystal that is arranged in parallel, and percentage by volume is at least 80%.Its width is 0.2～50.0 μ m, and length is 1.0～500 μ m.

Fig. 5 is the abstract model of single-roller method alloy casting piece forming process.

Among the figure, 1 is solid liquid interface, and 2 is solid phase, and 3 is band, and 4 is the molten bath, and 5 is nozzle, and 6 is liquid phase, and 7 is crucible, and 8 is single roller surface.

Embodiment

With example a kind of rare-earth alloy casting slice of the present invention and preparation method thereof is further described below, will helps to understand better the characteristics and the advantage of rare-earth alloy casting slice of the present invention and preparation method thereof.Protection range of the present invention is not limited by the following examples, and protection scope of the present invention is determined by claims.

Embodiment 1

The rare-earth alloy casting slice of present embodiment, its composition are that (wherein R is 31.4wt% to R for Fe, M) B, comprises that Nd is 31.1wt%, and Dy is 0.30wt%.M is 0wt%, and B is 1.1wt%, and surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 100g/s; getting rid of bandwidth is 50mm; cast temperature is 1300 ℃, and the water cooled rolls rotating speed is 0.2m/s, and wherein the cooling rate of fusing point～800 ℃ is 1 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 100 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.35mm, wherein the thickness distribution of 80% alloy casting piece in the scope of 0.25～0.45mm, the variances sigma of alloy casting piece thickness ²=0.011.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 85%, and its width is 0.2～20.0 μ m, and length is 2.0～350 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 2

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with resistance wire heating melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 1000g/s; getting rid of bandwidth is 150mm; cast temperature is 1350 ℃, and the water cooled rolls rotating speed is 1.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 5 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 80 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.4mm, wherein the thickness distribution of 90% alloy casting piece in the scope of 0.30～0.50mm, the variances sigma of alloy casting piece thickness ²=0.01.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 93%, and its width is 0.2～10.0 μ m, and length is 3.0～400 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 3

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with electric arc melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 5000g/s; getting rid of bandwidth is 300mm; cast temperature is 1390 ℃, and the water cooled rolls rotating speed is 2.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 7 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 50 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.32mm, wherein the thickness distribution of 95% alloy casting piece in the scope of 0.22～0.42mm, the variances sigma of alloy casting piece thickness ²=0.009.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 94%, and its width is 1.5～4.5 μ m, and length is 3.0～320 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 4

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 10000g/s; getting rid of bandwidth is 600mm; cast temperature is 1450 ℃, and the water cooled rolls rotating speed is 3.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 9 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 30 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.25mm, wherein the thickness distribution of 80% alloy casting piece in the scope of 0.20～0.30mm, the variances sigma of alloy casting piece thickness ²=0.008.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 95%, and its width is 1.0～4.0 μ m, and length is 3.0～250 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 5

The rare-earth alloy casting slice of present embodiment, its composition are that (wherein R is 29.0wt% to R for Fe, M) B, comprises Nd 16.0wt%, and Tb 5.0wt%, Dy are 8.0wt%.M is A10.52wt%, C μ 0.45wt%, and Co3.50wt%, Ga0.25wt%, Nb0.30wt%, B are 1.0wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 8000g/s; getting rid of bandwidth is 550mm; cast temperature is 1460 ℃, and the water cooled rolls rotating speed is 4.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 3 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 20 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein the thickness distribution of 80% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.007.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 95%, and its width is 1.5～3.8 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 6

The rare-earth alloy casting slice of present embodiment, its composition are that (wherein R is 29.0wt% to R for Fe, M) B, comprises Nd 16.0wt%, and Tb 5.0wt%, Dy are 8.0wt%.M is Al0.52wt%, C μ 0.45wt%, and Co3.50wt%, Ga0.25wt%, Nb0.30wt%, B are 1.0wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 6000g/s; getting rid of bandwidth is 400mm; cast temperature is 1400 ℃, and the water cooled rolls rotating speed is 3.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 5 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 10 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 90% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.006.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 96%, and its width is 1.0～3.7 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 7

The rare-earth alloy casting slice of present embodiment, its composition are that (wherein R is 29.0wt% to R for Fe, M) B, comprises Nd 16.0wt%, and Tb 5.0wt%, Dy are 8.0wt%.M is Al0.52wt%, Cu0.45wt%, and Co3.50wt%, Ga0.25wt%, Nb0.30wt%, B are 1.0wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 4000g/s; getting rid of bandwidth is 300mm; cast temperature is 1350 ℃, and the water cooled rolls rotating speed is 2.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 8 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 8 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 94% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.005.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 97%, and its width is 0.8～3.5 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 8

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 1000g/s; getting rid of bandwidth is 200mm; cast temperature is 1440 ℃, and the water cooled rolls rotating speed is 1.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 9 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 5 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 98% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.004.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 98%, and its width is 0.2～3.3 μ m, and length is 1.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 9

The rare-earth alloy casting slice of present embodiment, its composition be R (wherein R is 50.0wt% for Fe, M) B, comprises Nd 32.0wt%, Pr3.0wt%, Tb 5.0wt%, Dy are 10.0wt%.M is Al0.52wt%, Cu0.34wt%, and Co2.48wt%, Ga0.25wt%, Nb0.30wt%, B are 0wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 10000g/s; getting rid of bandwidth is 600mm; cast temperature is 1500 ℃, and the water cooled rolls rotating speed is 5.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 1 * 10 ²℃/s, 800 ℃～600 ℃ cooling rate is 100 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 1.0mm, wherein, the thickness distribution of 90% alloy casting piece in the scope of 0.90～1.10mm, the variances sigma of alloy casting piece thickness ²=0.01.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 80%, and its width is 1.0～50.0 μ m, and length is 2.0～500 μ m.The rare-earth alloy casting slice of present embodiment and the alloy of boracic are prepared into the sintering rare-earth iron boron magnet by the pairing gold process, and performance sees Table 1.

Embodiment 10

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 8000g/s; getting rid of bandwidth is 500mm; cast temperature is 1500 ℃, and the water cooled rolls rotating speed is 4.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 3 * 10 ²℃/s, 800 ℃～600 ℃ cooling rate is 80 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.6mm, wherein, the thickness distribution of 96% alloy casting piece in the scope of 0.50～0.70mm, the variances sigma of alloy casting piece thickness ²=0.008.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 84%, and its width is 1.0～40.0 μ m, and length is 2.0～400 μ m.The rare-earth alloy casting slice of present embodiment and the alloy of boracic are prepared into the sintering rare-earth iron boron magnet by the pairing gold process, and performance sees Table 1.

Embodiment 11

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 4000g/s; getting rid of bandwidth is 300mm; cast temperature is 1450 ℃, and the water cooled rolls rotating speed is 3.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 5 * 10 ²℃/s, 800 ℃～600 ℃ cooling rate is 60 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.5mm, wherein, the thickness distribution of 90% alloy casting piece in the scope of 0.45～0.55mm, the variances sigma of alloy casting piece thickness ²=0.006.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 88%, and its width is 1.0～30.0 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment and the alloy of boracic are prepared into the sintering rare-earth iron boron magnet by the pairing gold process, and performance sees Table 1.

Embodiment 12

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 1000g/s; getting rid of bandwidth is 150mm; cast temperature is 1430 ℃, and the water cooled rolls rotating speed is 2.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 7 * 10 ²℃/s, 800 ℃～600 ℃ cooling rate is 40 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.4mm, wherein, the thickness distribution of 90% alloy casting piece in the scope of 0.35～0.45mm, the variances sigma of alloy casting piece thickness ²=0.003.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 90%, and its width is 1.0～10.0 μ m, and length is 2.0～400 μ m.The rare-earth alloy casting slice of present embodiment and the alloy of boracic are prepared into the sintering rare-earth iron boron magnet by the pairing gold process, and performance sees Table 1.

Embodiment 13

The rare-earth alloy casting slice of present embodiment, its composition be R (wherein R is 30.5wt% for Fe, M) B, comprises Nd 24.0wt%, Pr3.5wt%, Tb 1.0wt%, Dy are 2.0wt%.M is Al0.30wt%, Mg0.10wt%, and Cu0.35wt%, Co1.50wt%, Ga0.25wt%, Nb0.30wt%, Ti0.15wt%, Si0.15wt%, B are 0.95wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 8000g/s; getting rid of bandwidth is 550mm; cast temperature is 1460 ℃, and the water cooled rolls rotating speed is 4.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 3 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 20 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein the thickness distribution of 90% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.006.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 95%, and its width is 1.5～3.8 μ m, and length is 2.0～200 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 14

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 6000g/s; getting rid of bandwidth is 400mm; cast temperature is 1400 ℃, and the water cooled rolls rotating speed is 3.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 5 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 10 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 92% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.004.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 96%, and its width is 1.0～3.7 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 15

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 1000g/s; getting rid of bandwidth is 200mm; cast temperature is 1350 ℃, and the water cooled rolls rotating speed is 1.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 7 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 5 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 94% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.003.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 97%, and its width is 0.4～3.5 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 16

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 500g/s; getting rid of bandwidth is 50mm; cast temperature is 1440 ℃, and the water cooled rolls rotating speed is 1.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 1 * 10 ⁴℃/s, 800 ℃～600 ℃ cooling rate is 2 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 96% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.002.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 98%, and its width is 0.2～3.3 μ m, and length is 1.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 17

The rare-earth alloy casting slice of present embodiment, its composition be R (wherein R is 31.5wt% for Fe, M) B, comprises Nd 24.0wt%, Gd4.5wt%, Tb 1.0wt%, Dy are 2.0wt%.M is Al0.30wt%, V0.10wt%, and Cu0.35wt%, Co1.50wt%, Cr0.35wt%, Nb0.30wt%, Mn0.25wt%, Si0.15wt%, N0.05wt%, B are 0.9wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with electric arc melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 9000g/s; getting rid of bandwidth is 600mm; cast temperature is 1520 ℃, and the water cooled rolls rotating speed is 5.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 1 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 15 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein the thickness distribution of 90% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.006.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 95%, and its width is 0.5～3.5 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 18

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with resistance wire heating melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 6000g/s; getting rid of bandwidth is 400mm; cast temperature is 1400 ℃, and the water cooled rolls rotating speed is 3.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 3 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 7 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.25mm, wherein, the thickness distribution of 92% alloy casting piece in the scope of 0.20～0.30mm, the variances sigma of alloy casting piece thickness ²=0.004.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 96%, and its width is 0.4～3.4 μ m, and length is 1.0～250 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 19

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 1000g/s; getting rid of bandwidth is 300mm; cast temperature is 1350 ℃, and the water cooled rolls rotating speed is 1.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 5 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 4 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.20mm, wherein, the thickness distribution of 94% alloy casting piece in the scope of 0.15～0.25mm, the variances sigma of alloy casting piece thickness ²=0.003.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 97%, and its width is 0.3～3.3 μ m, and length is 1.0～200 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 20

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 4000g/s; getting rid of bandwidth is 100mm; cast temperature is 1440 ℃, and the water cooled rolls rotating speed is 1.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 7 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 1 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.1mm, wherein, the thickness distribution of 96% alloy casting piece in the scope of 0.05～0.15mm, the variances sigma of alloy casting piece thickness ²=0.002.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 98%, and its width is 0.2～3.0 μ m, and length is 1.0～150 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 21

The rare-earth alloy casting slice of present embodiment, its composition be R (wherein R is 30wt% for Fe, M) B, comprises Nd 24.0wt%, La0.2wt%, Ce0.2wt%, Pr1.5wt%, Sm0.1wt%, Tb 1.0wt%, Dy are 2.0wt%, Ho1.0wt%.M is Al0.30wt%, Ga0.20wt%, and In0.10wt%, Co1.50wt%, Cr0.35wt%, Si0.15wt%, Ge0.15wt%, Sn0.10wt%, Pb0.10wt%, Mg0.15wt%, Ca0.10wt%, C0.10wt%, B are 0.95wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with electric arc melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 10000g/s; getting rid of bandwidth is 600mm; cast temperature is 1600 ℃, and the water cooled rolls rotating speed is 4.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 1 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 20 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.40mm, wherein the thickness distribution of 90% alloy casting piece in the scope of 0.30～0.50mm, the variances sigma of alloy casting piece thickness ²=0.01.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 90%, and its width is 0.5～5.5 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 22

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with resistance wire heating melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 6000g/s; getting rid of bandwidth is 400mm; cast temperature is 1550 ℃, and the water cooled rolls rotating speed is 3.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 3 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 15 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.35mm, wherein, the thickness distribution of 92% alloy casting piece in the scope of 0.30～0.40mm, the variances sigma of alloy casting piece thickness ²=0.005.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 95%, and its width is 0.4～4.4 μ m, and length is 1.0～350 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 23

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 1000g/s; getting rid of bandwidth is 200mm; cast temperature is 1450 ℃, and the water cooled rolls rotating speed is 1.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 5 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 10 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 94% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.003.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 96%, and its width is 0.3～3.5 μ m, and length is 1.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 24

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 500g/s; getting rid of bandwidth is 50mm; cast temperature is 1400 ℃, and the water cooled rolls rotating speed is 0.8m/s, and wherein the cooling rate of fusing point～800 ℃ is 7 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 1 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.25mm, wherein, the thickness distribution of 96% alloy casting piece in the scope of 0.20～0.25mm, the variances sigma of alloy casting piece thickness ²=0.002.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 98%, and its width is 0.2～3.0 μ m, and length is 1.0～250 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 25

The rare-earth alloy casting slice of present embodiment, its composition are that (wherein R is 32wt% to R for Fe, M) B, comprises Nd 22.0wt%, Pr1.0wt%, Eu0.5wt%, Gd1.0wt%, Dy are 2.5wt%, Er1.0wt%, Tm0.5wt%, Yb0.5wt%, Lu0.5wt%, Sc1.0wt%, Y1.5wt%.M is Ti0.30wt%, V0.20wt%, and Mn0.10wt%, Ni0.20wt%, Cu0.30wt%, Zn0.15wt%, Zr0.15wt%, Nb0.10wt%, Mo0.10wt%, Cd0.15wt%, C0.10wt%, N0.10wt%, B are 1.5wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 9000g/s; getting rid of bandwidth is 550mm; cast temperature is 1500 ℃, and the water cooled rolls rotating speed is 3.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 2 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 50 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.40mm, wherein the thickness distribution of 92% alloy casting piece in the scope of 0.30～0.50mm, the variances sigma of alloy casting piece thickness ²=0.01.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 90%, and its width is 0.5～6.5 μ m, and length is 2.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 26

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with resistance wire heating melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 6000g/s; getting rid of bandwidth is 400mm; cast temperature is 1470 ℃, and the water cooled rolls rotating speed is 2.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 3 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 30 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.35mm, wherein, the thickness distribution of 93% alloy casting piece in the scope of 0.30～0.40mm, the variances sigma of alloy casting piece thickness ²=0.005.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 95%, and its width is 0.4～5.0 μ m, and length is 1.0～350 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 27

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 3000g/s; getting rid of bandwidth is 300mm; cast temperature is 1430 ℃, and the water cooled rolls rotating speed is 1.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 5 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 20 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 94% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.003.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 96%, and its width is 0.3～3.5 μ m, and length is 1.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 28

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 1000g/s; getting rid of bandwidth is 100mm; cast temperature is 1340 ℃, and the water cooled rolls rotating speed is 1.2m/s, and wherein the cooling rate of fusing point～800 ℃ is 9 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 10 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.25mm, wherein, the thickness distribution of 96% alloy casting piece in the scope of 0.20～0.25mm, the variances sigma of alloy casting piece thickness ²=0.002.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 98%, and its width is 0.2～3.0 μ m, and length is 1.0～250 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 29

The rare-earth alloy casting slice of present embodiment, its composition be R (wherein R is 28.5wt% for Fe, M) B, comprises Nd 22.5wt%, Pr3.0wt%, Tb1.0wt%, Dy are 2.0wt%.M is Ti0.50wt%, V0.50wt%, and Co5.0wt%, Ni2.4wt%, Cu0.50wt%, Al0.30wt%, Zr0.20wt%, Nb0.50wt%, Mo0.10wt%, B are 1.05wt%, surplus is Fe.

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 8000g/s; getting rid of bandwidth is 600mm; cast temperature is 1460 ℃, and the water cooled rolls rotating speed is 4.0m/s, and wherein the cooling rate of fusing point～800 ℃ is 2 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 25 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.40mm, wherein the thickness distribution of 92% alloy casting piece in the scope of 0.30～0.50mm, the variances sigma of alloy casting piece thickness ²=0.01.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 90%, and its width is 0.5～8.0 μ m, and length is 2.0～400 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 30

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with resistance wire heating melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 5000g/s; getting rid of bandwidth is 500mm; cast temperature is 1430 ℃, and the water cooled rolls rotating speed is 2.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 3 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 15 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.35mm, wherein, the thickness distribution of 93% alloy casting piece in the scope of 0.30～0.40mm, the variances sigma of alloy casting piece thickness ²=0.005.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 95%, and its width is 0.4～5.0 μ m, and length is 1.0～350 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 31

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the high-frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 3000g/s; getting rid of bandwidth is 400mm; cast temperature is 1400 ℃, and the water cooled rolls rotating speed is 1.5m/s, and wherein the cooling rate of fusing point～800 ℃ is 5 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 10 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.30mm, wherein, the thickness distribution of 94% alloy casting piece in the scope of 0.25～0.35mm, the variances sigma of alloy casting piece thickness ²=0.003.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 96%, and its width is 0.3～3.7 μ m, and length is 1.0～300 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Embodiment 32

Its preparation method is: under vacuum or argon shield; form rare-earth alloy molten solution with the Medium frequency induction melting; be cast on the water-cooled copper roller of rotation by the mode of casting groove then with planar flows; the alloy flow quantity is 1000g/s; getting rid of bandwidth is 100mm; cast temperature is 1360 ℃, and the water cooled rolls rotating speed is 1.2m/s, and wherein the cooling rate of fusing point～800 ℃ is 9 * 10 ³℃/s, 800 ℃～600 ℃ cooling rate is 1 ℃/s.The average thickness μ that obtains rare-earth alloy casting slice is 0.25mm, wherein, the thickness distribution of 96% alloy casting piece in the scope of 0.20～0.25mm, the variances sigma of alloy casting piece thickness ²=0.002.Principal phase Nd in this alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is 98%, and its width is 0.2～3.3 μ m, and length is 1.0～250 μ m.The rare-earth alloy casting slice of present embodiment is prepared into the sintering rare-earth iron boron magnet, and performance sees Table 1.

Comparative example 1

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 1 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 1 again, and performance sees Table 1.

Comparative example 2

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 2 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 2 again, and performance sees Table 1.

Comparative example 3

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 3 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 3 again, and performance sees Table 1.

Comparative example 4

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 4 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 4 again, and performance sees Table 1.

Comparative example 5

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 5 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 5 again, and performance sees Table 1.

Comparative example 6

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 6 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 6 again, and performance sees Table 1.

Comparative example 7

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 7 ²=0.018 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 7 again, and performance sees Table 1.

Comparative example 8

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 8 ²=0.018 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 8 again, and performance sees Table 1.

Comparative example 9

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 9 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 9 again, and performance sees Table 1.

Comparative example 10

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 10 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 10 again, and performance sees Table 1.

Comparative example 11

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 11 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 11 again, and performance sees Table 1.

Comparative example 12

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 12 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 12 again, and performance sees Table 1.

Comparative example 13

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 13 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 13 again, and performance sees Table 1.

Comparative example 14

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 14 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 14 again, and performance sees Table 1.

Comparative example 15

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 15 ²=0.018 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 15 again, and performance sees Table 1.

Comparative example 16

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 16 ²=0.018 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 16 again, and performance sees Table 1.

Comparative example 17

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 17 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 17 again, and performance sees Table 1.

Comparative example 18

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 18 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 18 again, and performance sees Table 1.

Comparative example 19

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 19 ²=0.018 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 19 again, and performance sees Table 1.

Comparative example 20

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 20 ²=0.018 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 20 again, and performance sees Table 1.

Comparative example 21

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 21 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 21 again, and performance sees Table 1.

Comparative example 22

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 22 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 22 again, and performance sees Table 1.

Comparative example 23

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 23 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 23 again, and performance sees Table 1.

Comparative example 24

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 24 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 24 again, and performance sees Table 1.

Comparative example 25

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 25 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 25 again, and performance sees Table 1.

Comparative example 26

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 26 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 26 again, and performance sees Table 1.

Comparative example 27

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 27 ²=0.018 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 27 again, and performance sees Table 1.

Comparative example 28

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 28 ²=0.018 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 28 again, and performance sees Table 1.

Comparative example 29

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 29 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 29 again, and performance sees Table 1.

Comparative example 30

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 30 ²=0.021 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 30 again, and performance sees Table 1.

Comparative example 31

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 31 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 31 again, and performance sees Table 1.

Comparative example 32

Be prepared into the variances sigma of thickness by the casting blade technolgy with the congruent rare earth alloy of embodiment 32 ²=0.020 alloy casting piece becomes sintered magnet by the prepared identical with embodiment 32 again, and performance sees Table 1.

Table 1

Claims

1. rare-earth alloy casting slice is characterized in that: at least 80% alloy casting piece thickness distribution in the scope of [μ-0.1mm, μ+0.1mm], σ ²≤ 0.011mm ², wherein μ is the average thickness of alloy casting piece, scope is 0.1～1.0mm; σ ²Be the variance of alloy casting piece thickness, the degree of scatter of expression alloy casting piece thickness.

2. a kind of rare-earth alloy casting slice according to claim 1 is characterized in that: principal phase Nd in the alloy casting piece ₂Fe ₁₄B crystal grain is column crystal, and the percentage by volume of column crystal is at least 80%, and the width of column crystal is 0.2～50.0 μ m, and length is 1.0～500 μ m.

3. rare-earth alloy casting slice according to claim 1, it is characterized in that: the composition of alloy casting piece is R (Fe, M) B, R represents one or more in 17 kinds of rare earth elements that comprise Sc, Y, percentage composition is 26.0～50.0wt%, M is among transition element except that Fe, Al, Ga, In, C, N, Si, Ge, Sn, Pb, Mg, the Ca one or more, percentage composition is 0～10.0wt%, B is a boron, percentage composition is 0～1.5wt%, and surplus is iron and unavoidable impurities.

4. rare-earth alloy casting slice according to claim 1, it is characterized in that: the composition of alloy casting piece is R (Fe, M) B, R represents one or more in 17 kinds of rare earth elements that comprise Sc, Y, percentage composition is 26.0～38.0wt%, M is among transition element except that Fe, Al, Ga, In, C, N, Si, Ge, Sn, Pb, Mg, the Ca one or more, percentage composition is 0～10.0wt%, B is a boron, percentage composition is 0.8～1.5wt%, and surplus is iron and unavoidable impurities.

5. rare-earth alloy casting slice according to claim 1, it is characterized in that: the composition of alloy casting piece is R (Fe, M) B, R represents one or more in 17 kinds of rare earth elements that comprise Sc, Y, percentage composition is 28.0～35.0wt%, M is one or more among Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ta, W, Al, Ga, C, Ge, Sn, Pb, Mg, the Ca, percentage composition is 0～8.0wt%, B is a boron, percentage composition is 0.8～1.5wt%, and surplus is iron and unavoidable impurities.

6. rare-earth alloy casting slice according to claim 1 is characterized in that: the thickness distribution of at least 90% alloy casting piece in the scope of [μ-0.1mm, μ+0.1mm], σ ²≤ 0.01mm ²

7. rare-earth alloy casting slice according to claim 1 is characterized in that: the thickness distribution of at least 95% alloy casting piece in the scope of [μ-0.1mm, μ+0.1mm], σ ²≤ 0.008mm ²

8. rare-earth alloy casting slice according to claim 1 is characterized in that: the thickness distribution of at least 80% alloy casting piece in the scope of [μ-0.05mm, μ+0.05mm], σ ²≤ 0.008mm ²

9. rare-earth alloy casting slice according to claim 1 is characterized in that: the thickness distribution of at least 90% alloy casting piece in the scope of [μ-0.05mm, μ+0.05mm], σ ²≤ 0.006mm ²

10. rare-earth alloy casting slice according to claim 1 is characterized in that: the average thickness μ of alloy casting piece is 0.2mm～0.5mm.

11. rare-earth alloy casting slice according to claim 1 is characterized in that: principal phase Nd in the alloy casting piece ₂Fe ₁₄The percentage by volume of B is at least 85%.

12. rare-earth alloy casting slice according to claim 1 is characterized in that: principal phase Nd in the alloy casting piece ₂Fe ₁₄The B percentage by volume is at least 91%.

13. prepare the method for any described rare-earth alloy casting slice in the claim 1～12, it is characterized in that: adopt casting sheet method the rare earth alloy liquid of fusion to be cast to by the casting groove on the water cooled rolls of rotation and form the uniform alloy casting piece of thickness, wherein the cooling rate of fusing point～800 ℃ is 10 ²～10 ⁴℃/s, 800 ℃～600 ℃ cooling rate be 100 ℃/below the s.

14. the preparation method of rare-earth alloy casting slice according to claim 13 is characterized in that: the mode of heating of molten alloy is a kind of in Medium frequency induction melting, high-frequency induction melting, electric arc melting, the resistance wire heating melting.

15. the preparation method of rare-earth alloy casting slice according to claim 13 is characterized in that: alloy flow quantity size is adjustable and can stablize control in 100g/s～10000g/s scope.

16. the preparation method of rare-earth alloy casting slice according to claim 13 is characterized in that: it is adjustable and can stablize control in 50mm～600mm scope that rare earth alloy liquid is cast to width on the water cooled rolls of rotation.

17. the preparation method of rare-earth alloy casting slice according to claim 13 is characterized in that: cast temperature is adjustable and can stablize control in 1300 ℃～1600 ℃ scopes.

18. the preparation method of rare-earth alloy casting slice according to claim 13 is characterized in that: the water cooled rolls rotating speed is adjustable and can stablize control in 0.2m/s～5.0m/s scope.

19. an alloy powder that contains rare earth is characterized in that, is prepared by the mode of the described rare-earth alloy casting slice of claim 1～12 by Mechanical Crushing or hydrogen fragmentation.

20. a rare earth magnet is characterized in that by the described rare-earth alloy casting slice of claim 1～12 being that raw material is made.