CN102436889B - Low-weight-loss neodymium iron boron magnetic material with Titanium, zirconium and gallium compound addition and preparation method thereof - Google Patents

Abstract

The invention discloses a NdFeB magnetic material compounded with titanium, zirconium and gallium, belongs to the technical field of magnetic materials, and solves the technical problems of high preparation cost and high weight loss of the existing NdFeB magnetic material. The components and mass percentages of the NdFeB magnetic material compounded with titanium, zirconium and gallium in the present invention are: Nd: 25%-30.1%, B: 1%-1.5%, Dy: 0.3%-5%, Al: 0.5%- 0.6%, Zr: 0.2%, Ti: 0.2%, Co: 0.6-0.8%, Cu: 0.2%-0.4%, Ga: 0.2%, and the balance is Fe. At the same time, the invention also discloses a preparation method for the above-mentioned magnetic material, which includes the steps of smelting, powder making, molding and sintering. The invention uses relatively cheap metal elements titanium and zirconium to replace the more expensive Dy and Ga, thereby achieving the benefit of reducing the cost by 10% to 20%, and the weight loss of the invention is small, which meets the requirements of the existing NdFeB requirements in various application areas.

Description

Low weight loss neodymium iron boron magnetic material compounded with titanium zirconium gallium and preparation method thereof

technical field

The invention relates to a magnetic material and a preparation method thereof, in particular to a high-performance low-weight-loss neodymium-iron-boron magnetic material compounded with titanium, zirconium and gallium, and a preparation method thereof.

Background technique

In the process of the transfer of the world's manufacturing and new material industry centers to China, the new material industry as the basis of high-tech industries has attracted much attention. As an important part of the new material industry, rare earth permanent magnet materials, especially NdFeB industry, have also entered It has entered a critical period of development; my country has initially formed its own industrial system in the production of NdFeB. Production has accounted for 40% of the world's total.

Neodymium iron boron (NdFeB) magnetic material is the third generation of permanent magnet material developed in the early 1980s. It has strong magnetic properties and is the strongest permanent magnet today, known as the "permanent magnet king". Because of its good cost performance, NdFeB permanent magnet materials are widely used in international and domestic emerging industries and pillar industries, such as computer industry, information industry, communication industry, automobile industry, nuclear magnetic resonance imaging industry, office automation, etc. With the improvement of requirements for magnet devices, especially the development of devices used in the field of information and communication to the direction of miniaturization, light weight, high speed, low noise, etc., the performance of magnets is required to be gradually improved, and the amount of high-performance NdFeB magnets will be reduced. It will continue to increase, so high-performance NdFeB permanent magnet materials are the focus of current industry development.

However, the production of high-performance NdFeB magnetic materials requires the use of more rare and precious metals such as gallium and cobalt. Due to the sharp rise in the prices of non-ferrous metals and rare earth elements in recent years, this has led to the production cost of high-performance NdFeB magnetic materials. High, and the existing high-performance NdFeB permanent magnet materials have poor corrosion resistance and high weight loss, which seriously restricts the rapid development of the sintered NdFeB magnetic industry.

In the prior art, relatively cheap metals such as zirconium are added to replace relatively expensive metals such as niobium and cobalt in NdFeB magnets, thereby reducing production costs. Niobium NdFeB permanent magnet material, the composition ratio of the permanent magnet material is (28-35)% praseodymium neodymium alloy, (1-10)% gadolinium, (0.1-0.5)% zirconium, (0.95-1.3) % boron, (0.1-1.5)% aluminum, (0.01-0.3)% copper, and the rest are iron and unavoidable impurities, the above are percentages by weight. Although the magnetic material adjusts the alloy composition and adds the metal element zirconium to replace the niobium element in the NdFeB alloy. However, the addition amount of zirconium element is only 0.1%-0.5%, and the magnetic material also contains 1-10% rare earth element gadolinium, which still cannot effectively reduce the cost. Another example is a Chinese patent application (publication number: CN1862717A) relating to an ultra-high coercive force sintered NdFeB magnetic material and its preparation method. The composition and weight percentage of the NdFeB magnetic material are Nd: 21% to 26%; Dy: 3% to 10%; Tb: 0.2% to 6%; Co: 2% to 7%; Nb: 0.2% to 4%; Cu: 0.05% to 0.7%; Ga: 0.01% to 0.6%; 0.6% to 1.2%; the rest is Fe. Although sintered NdFeB magnets with intrinsic coercive force ≥ 35kOe (2786kA/m) can be prepared by traditional ordinary ingot casting method. But the usage of its precious metals is still on the high side, for example, the mass percentage of cobalt (Co) is 2%-7%, and the mass percentage of dysprosium (Dy) is 3%-10%, and the cost is still high, and it is only for neodymium Improving the working temperature of iron boron cannot reduce its weight loss problem, so there is no improvement in the corrosion resistance of magnetic materials.

Contents of the invention

Aiming at the defects in the prior art, the invention provides a high-performance, low-cost, corrosion-resistant, and low-weight-loss titanium-zirconium-gallium compound-added NdFeB magnetic material.

The above object of the present invention can be achieved through the following technical solutions: a low-weight-loss NdFeB magnetic material compounded with titanium, zirconium and gallium, characterized in that: the composition and mass percentage of the NdFeB magnetic material are: Nd: 25.0%-32.0%, B: 1.0%-1.5%, Dy: 0.3%-5.0%, Al: 0.3%-0.8%, Zr: 0.05-0.5%, Ti: 0.05-0.5%, Co: 0.2-0.8% , Cu: 0.05%-0.4%, Ga: 0.05-0.5%, and the balance is Fe.

The sintered NdFeB magnetic material has a multi-phase structure, and the oxidation ability of each phase is different. The Nd-rich phase and B-rich phase distributed at the grain boundary are prone to preferential oxidation, forming intergranular corrosion. In addition, the density of the magnet is not high, and the oxide is relatively loose and the porosity is large. It is difficult to form an oxide protective film on the surface of the magnet. Once oxidized, it will cause a chain reaction and accelerate oxidation; and because the main phase of the magnet is Nd:Fe:B The volume fraction of the phase is generally above 90%. When an electrochemical localized corrosion cell is formed, it has the characteristics of a small anode and a large cathode. The corrosion current density of the Nd-rich phase and the B-rich phase at the grain boundary is relatively large, which accelerates the intergranular corrosion. and destruction.

First of all, the present invention adopts the compound addition of titanium, zirconium and gallium, and limits the amount of addition. These alloys can meet the requirements of magnets for grain boundary phases, have low melting points and good wettability. It can smooth the main phase grains, refine the crystallization, make the grain boundary phase distribution uniform, and weaken the magnetic exchange coupling effect; it can enter the Nd:Fe:B main phase structure through diffusion during sintering, and partially replace Nd or Fe , so as to improve the corrosion resistance of the main phase of the magnet, the density of the magnet increases and the pores are less, and the corrosion weight loss of the final magnetic material will be smaller.

Secondly, the present invention adds an appropriate amount of titanium (Ti) and zirconium (Zr) to replace part of Dy and Co, which can not only keep the remanence from decreasing but also increase the coercive force, and also play a good role in reducing costs . Among them, the Zr element reduces the sensitivity of the NdFeB magnetic material to the sintering temperature, improves the sintering temperature resistance of the magnet, and does not cause abnormal grain growth. Composite addition of Zr, Ga and Ti overcomes the problem of poor stability of magnet performance caused by uneven temperature field distribution in the sintering furnace, and finally prepares a magnet with high energy product and stable performance. However, if the three components are added too much, the magnetic properties of the entire magnetic material will be poor.

Preferably, the composition and mass percentage of the NdFeB magnetic material are: Nd: 26.5%-30.0%, B: 1.0%-1.3%, Dy: 1.0%-4.0%, Al: 0.4%-0.6%, Zr: 0.2-0.4%, Ti: 0.2-0.4%, Co: 0.2-0.5%, Cu: 0.05%-0.25%, Ga: 0.2-0.4%, the balance is Fe; using this optimized mass percentage, is A better optimization and limitation of the invention.

Further preferably, the composition and mass percentage of the NdFeB magnetic material are: Nd: 28.0%, B: 1.0%, Dy: 3.0%, Al: 0.5%, Zr: 0.2%, Ti: 0.2%, Co: 0.5%, Cu: 0.1%, Ga: 0.2%, and the balance is Fe.

Another object of the present invention is to provide the preparation method of the above-mentioned NdFeB magnetic material, which comprises the following steps:

S1: Melting: According to the composition and mass percentage of the NdFeB magnetic material according to any one of claims 1 to 3, the raw materials are mixed, and the raw materials are put into a vacuum belt furnace and completely melted, and then poured into a thickness of 0.1mm -0.5mm flinger;

S2: Milling: Put the flakes obtained in step S1 into the hydrogen crushing furnace, feed hydrogen gas into the hydrogen crushing furnace until the pressure in the furnace reaches 0.1-0.5Mpa, then close the hydrogen valve, and raise the temperature of the hydrogen crushing furnace to 500°C- After dehydrogenation at 700°C for 2-8 hours, put the dehydrogenated flakes into the jet mill to make powder and control the particle size of the powder to 1-10 μm, then add antioxidant organic additives to the powder and stir for 30-90 minutes ;

S3: Molding: Put the stirred powder into the molding press mold and apply a magnetic field for orientation. After orientation, press molding, demagnetization and vacuum packaging, and put the vacuum-packed green body into the isostatic press to pressurize 100-250Mpa , Hold the pressure for 2-6 minutes and take it out;

S4: Sintering: put the green body obtained after forming in step S3 into a sintering furnace, sinter at a temperature of 1050°C-1200°C for 3-8 hours, temper at 750-950°C for 0.5-3 hours, and then air-cool, The air-cooled green body is heated again to 400-700° C., tempered for 2-6 hours, and taken out to obtain a finished product.

Cooling water is used for cooling after pouring in step S1 of the present invention, and the temperature of the cooling water is lower than 25°C. As a preference, the step of melting the raw material in the vacuum belt furnace includes: vacuumizing the air in the vacuum belt furnace to 3-8Pa Heat and smelt until the temperature rises to 950-1100°C, close the vacuum valve, fill the vacuum belt furnace with argon until the pressure in the vacuum belt furnace reaches 0.4-0.6MPa, then raise the temperature to 1450-1490°C to completely melt the raw materials , pouring after refining for 10-15 minutes, the thickness of the flakes after pouring is preferably controlled at 0.2-0.3mm.

In step S2, the hydrogen crushing process is used to make powder. The hydrogen crushing process can greatly improve the production efficiency of the subsequent process, so that the original NdFeB powder has a good particle distribution and shape, and provides a basis for sintering to refine the grains, which can The coercive force of the material is greatly improved, and the formulation cost is indirectly reduced.

In the molding process in step S3, the NdFeB powder is subjected to the action of a magnetic field in the cavity of the press, and the magnetic powder particles are oriented and arranged, wherein the higher the degree of powder orientation, the higher the residual magnetism of the sintered material. Improving the orientation degree of the material during molding is also one of the methods to improve the remanence of the material, which can also indirectly reduce the formulation cost of the material. The invention improves the orientation degree of the molding material by improving the fluidity of the powder material, so that the powder is more easily arranged along the distribution of the orientation magnetic field. The main method to improve the fluidity of the powder is to add an anti-oxidation organic additive during the powder stirring stage; as a preference, the present invention performs two orientations to improve the remanence of the material when the magnetic field is applied.

Selecting a reasonable sintering process in step S4 is the key to ensure that the material has certain magnetic properties. After high-temperature sintering, it can have a certain remanence and coercive force, and then tempering can significantly improve the coercive force of magnetic materials, and indirectly reduce the cost of material formulation.

Preferably, the dehydrogenation temperature in step S2 is 550° C.-650° C., the dehydrogenation time is 3-6 hours, and the particle size of the powder after pulverization is controlled at 3-6 μm.

As a preference, the antioxidant organic auxiliary agent described in step S2 is composed of organic substances containing electron-donating groups, borates and gasoline, and the volume ratio of organic substances containing electron-donating groups is 10-80%. The volume ratio is 2-75%, and the volume ratio of gasoline is 10-80%. The organic component containing electron-donating groups is one or two kinds of aniline, alkyl, amino, methoxy, and hydroxyl groups. and the above mixture; the added amount of the antioxidant additive is 0.02%-0.04% by weight of the powder.

Preferably, in step S4, the sintering temperature is 1060°C-1150°C, the sintering time is 4-6 hours, and after tempering at 800-900°C for 1-2 hours, it is air-cooled, and the air-cooled green body is heated again to After tempering at 500-600°C for 3-5 hours.

In summary, the present invention has the following advantages:

1. The present invention uses relatively cheap metal elements titanium and zirconium to replace Dy and Ga, which are more expensive, thereby reducing the cost by 10%-20%. In the era of rapidly increasing rare earth prices, it greatly increases Cost competitiveness, and reduce the use of strategic resources Co, Dy.

2. On the basis of reducing the amount of Co used and without increasing the cost of the product, the present invention improves the structure of the crystal through the compound addition of Ti and Ga and the improvement of the process, so that the weight loss of the product is reduced. Under the test conditions of atmospheric pressure, temperature 130°C, relative humidity 100%, and time 168 hours, the weight loss of the NdFeB magnetic material compounded with titanium, zirconium and gallium of the present invention is less than 0.5mg/cm ² , which fully meets the requirements of the existing NdFeB Highest demands in every field of application.

3. The method of the present invention prepares NdFeB magnetic materials with higher performance, reduces production costs, and is suitable for large-scale industrial production.

Detailed ways

The technical solutions of the present invention will be further specifically described below through specific examples; but the present invention is not limited to these examples.

Example 1:

Ingredients: Proportion according to the contents stated in the following composition ratio table.

Taking the smelting of 600Kg NdFeB alloy as an example, the distribution ratio of each component is shown in Table 1-1:

Table 1-1: The distribution ratio of each component (% by weight) in Example 1

Element Nd B Dy Al Zr Ti Co Cu Ga Fe Embodiment 1 30.1 1.3 0.8 0.6 0.2 0.4 0.5 0.25 0.2 Surplus

According to the above proportioning composition, the raw materials are mixed and put into the vacuum belt furnace.

(1) Smelting: The raw materials that have been cleaned on the surface are prepared according to the alloy composition ratio; placed in a medium-vacuum belt throwing furnace, when the air in the vacuum belt throwing furnace is evacuated to 4-5Pa, heating and smelting is started until When the ingredients in the furnace turn red, close the vacuum valve, fill in argon to 0.4MPa, and raise the temperature at 1490°C until the ingredients are completely melted, and pour after refining for 10-15 minutes. The thickness of the flakes should be controlled at Between 0.2mm and 0.3mm, use cooling water for cooling, and the temperature of the cooling water is lower than 25°C.

(2) Milling: Place the flakes in a hydrogen crushing furnace, and pass in hydrogen gas. After the product is completely absorbed by hydrogen and stabilized at 0.2Mpa, close the hydrogen valve, raise the temperature to 550°C, and carry out dehydrogenation for 6 hours. After the dehydrogenation is completed Put the flakes into a jet mill to make powder, control the particle size of the powder to be 3-5 μm, then add 0.02% by weight of anti-oxidation organic additive to the powder and stir for 90 minutes.

(3) Molding: The stirred powder is weighed according to the specified weight, put into the mold of the molding press, add a magnetic field and perform orientation twice to improve the orientation degree of magnetic properties, press molding after orientation, and then demagnetize to take out the green body. And quickly vacuum-package, then put the good green body of vacuum-package into the isostatic press and pressurize 250Mpa, take out after keeping the pressure for 2 minutes.

(4) Sintering: Put the green body into a sintering pot, put it into a sintering furnace for sintering, sinter at a sintering temperature of 1150°C for 4 hours, temper at 800°C for 2 hours, then air-cool, then heat up to 500°C and temper for 5 Take it out in an hour, and the sintered NdFeB magnet process is completed.

The sintered NdFeB magnet produced according to the above process uses 0.4% titanium, 0.2% zirconium, and 0.2% gallium to replace 2% cobalt and 0.4% dysprosium, reducing the amount of 0.1% gallium to make sintered NdFeB magnets. Boron magnetic materials are tested in accordance with the provisions of GB/T3217 permanent magnet (hard magnetic) material magnetic test method, and the magnetic properties are shown in Table 1-2:

Table 1-2: Magnetic properties of NdFeB magnets compounded with zirconium, titanium, and gallium (and compared with NdFeB magnets without added zirconium, titanium, and gallium)

Comparing the above data, it can be seen that the magnetic properties of the magnets have been improved by using 0.4% titanium, 0.2% zirconium, and 0.2% gallium to replace 2% cobalt, 0.4% dysprosium, and reducing the amount of 0.1% gallium. , and cost savings of 10 to 20%.

Embodiment two:

Ingredients: Proportion according to the contents stated in the following composition ratio table.

Taking the smelting of 600Kg NdFeB alloy as an example, the distribution ratio of each component is shown in Table 2-1:

Table 2-1: The distribution ratio of each component in Example 2

Element Nd B Dy Al Zr Ti Co Cu Ga Fe Example 2 28.0 1.0 4.0 0.5 0.2 0.2 0.6 0.1 0.2 Surplus

According to the above proportioning composition, the raw materials are mixed and put into the vacuum belt furnace.

(1) Smelting: The raw materials that have been cleaned on the surface are prepared according to the alloy composition ratio; placed in a medium-vacuum belt throwing furnace, when the air in the vacuum belt throwing furnace is evacuated to 4-5Pa, heating and smelting is started until When the ingredients in the furnace turn red, close the vacuum valve, fill in argon to 0.5MPa, and raise the temperature at 1450°C until the ingredients are completely melted, and pour after refining for 10-15 minutes. The thickness of the flakes should be controlled at Between 0.2mm and 0.3mm, use cooling water for cooling, and the temperature of the cooling water is lower than 25°C.

(2) Milling: Place the flakes in a hydrogen crushing furnace, and pass in hydrogen gas. After the product is completely hydrogen-absorbed to 0.3Mpa and stabilized, close the hydrogen valve, raise the temperature to 600°C, and perform dehydrogenation for 4 hours. After the dehydrogenation is completed The flakes were put into a jet mill to make powder, and the particle size of the powder was controlled at 3-5 μm, and then 0.04% by weight of the anti-oxidation organic additive was added to the powder and stirred for 60 minutes.

(3) Molding: The stirred powder is weighed according to the specified weight, put into the mold of the molding press, add a magnetic field and perform orientation twice to improve the orientation degree of magnetic properties, press molding after orientation, and then demagnetize to take out the green body. And quickly vacuum-package, then put the good green body of vacuum-package into the isostatic press and pressurize 180Mpa, take out after keeping the pressure for 4 minutes.

(4) Sintering: Put the green body into a sintering pot, put it into a sintering furnace for sintering, sinter at a sintering temperature of 1100°C for 5 hours, temper at 850°C for 1.5 hours, then air-cool, then heat up to 600°C and temper for 4 Take it out in an hour, and the sintered NdFeB magnet process is completed.

The sintered NdFeB magnet produced according to the above process uses 0.2% titanium, 0.2% zirconium, and 0.2% gallium to replace 2% cobalt and 0.4% dysprosium, reducing the amount of gallium by 0.1%, and making sintered neodymium iron Boron alloys are tested according to the provisions of GB/T3217 permanent magnet (hard magnetic) material magnetic test method, and the magnetic properties are shown in Table 2-2:

Table 2-2: Magnetic properties of NdFeB magnets compounded with zirconium, titanium, and gallium (and compared with NdFeB magnets without added zirconium, titanium, and gallium)

Comparing the above data, it can be seen that the magnetic properties of the magnet have been improved to a certain extent after using 0.2% titanium, 0.2% zirconium, and 0.2% gallium to replace 2% cobalt and 0.4% dysprosium, and reduce the amount of 0.1% gallium. , and cost savings of 10 to 20%.

Embodiment three:

Ingredients: Proportion according to the content stated in the following composition ratio table

Taking the smelting of 600Kg NdFeB alloy as an example, the distribution ratio of each component is shown in Table 3-1:

Table 3-1: The distribution ratio of each component in Example 3

Element Nd B Dy Al Zr Ti Co Cu Ga Fe Example three 25.0 1.5 5.0 0.3 0.3 0.1 0.4 0.2 0.1 Surplus

According to the above proportioning composition, each raw material is mixed and charged into a vacuum belt throwing furnace, and other preparation procedures are the same as in Example 2.

The sintered NdFeB magnet produced according to the above process uses 0.1% titanium, 0.3% zirconium, and 0.1% gallium to replace 2% cobalt and 0.4% dysprosium, reducing the amount of 0.2% gallium to make sintered neodymium iron Boron alloys are tested in accordance with the provisions of GB/T3217 permanent magnet (hard magnetic) material magnetic test method, and the magnetic properties are shown in Table 3-2:

Table 3-2: Magnetic properties of NdFeB magnets compounded with zirconium, titanium, and gallium (and compared with NdFeB magnets without added zirconium, titanium, and gallium)

Comparing the above data, it can be seen that the magnetic properties of the magnet have been improved to a certain extent after using 0.1% titanium, 0.3% zirconium, and 0.1% gallium to replace 2% cobalt and 0.4% dysprosium, and reduce the amount of 0.2% gallium. , and cost savings of 10 to 20%.

Composite addition of titanium, zirconium and gallium formula can also significantly improve the low weight loss effect of the product. Under the test conditions of 3 atmospheric pressure, temperature 130 ℃, relative humidity 100%, and time of 168 hours, the composite addition of titanium, zirconium and gallium formula is obviously better It does not add titanium, zirconium and gallium to the formula. This is mainly because titanium and zirconium elements belong to high-melting alloy elements, while gallium elements belong to low-melting alloy elements. In the present invention, the content of high-melting alloy elements increases and the content of low-melting alloy elements decreases; titanium elements form Ti-B or Fe -Ti-B intergranular phase, zirconium element forms Zr-B or Fe-Zr-B intergranular phase, these intergranular phases have a relatively positive corrosion potential, which can weaken the reaction and decomposition of intergranular phases and delay grain boundary corrosion generation.

The weight loss comparison results of both sides are shown in Table 4:

Table 4: The weight loss rate of the present invention and conventional NdFeB magnets without adding zirconium and titanium

Based on the above test data of sintered NdFeB magnets, the use of titanium, zirconium, and gallium composite additions to replace relatively expensive dysprosium, gallium and other rare metals can improve the crystal structure, improve the performance of NdFeB magnets, reduce the weight loss rate of products, and increase The corrosion resistance of the product has achieved the purpose of reducing the production cost of the enterprise and improving product performance.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (2)

1. the low weightless neodymium-iron-boron magnetic material of the compound interpolation of a titanium zirconium gallium, it is characterized in that: the component of described neodymium-iron-boron magnetic material and mass percent are: Nd:28.0%, B:1.0%, Dy:3.0%, Al:0.5%, Zr:0.2%, Ti:0.2%, Co:0.5%, Cu:0.1%, Ga:0.2%, surplus is Fe; The preparation method of the low weightless neodymium-iron-boron magnetic material of the described compound interpolation of titanium zirconium gallium comprises the following steps:

S1: melting: by component and the mass percent proportioning raw material of described neodymium-iron-boron magnetic material, and this raw material is put into vacuum spun furnace, when being evacuated to 3-8Pa, the air of vacuum spun furnace heats melting until temperature is closed vacuum valve while being warming up to 950-1100 DEG C, toward being filled with argon gas in vacuum spun furnace until in vacuum spun furnace pressure reach and be warming up to 1450 DEG C-1490 DEG C after 0.4-0.6MPa raw material is melted completely, after fusing, pour into the rejection tablet that thickness is 0.1mm-0.5mm completely;

S2: powder process: the rejection tablet that step S1 is obtained is inserted in hydrogen crushing furnace, in hydrogen crushing furnace, pass into hydrogen until furnace pressure is closed hydrogen valve after reaching 0.1-0.5Mpa, dehydrogenase 13-6 hour after hydrogen crushing furnace is warming up to 550 DEG C-650 DEG C, rejection tablet after dehydrogenation being put into airflow milling powder process and control powder particles is 3-6 μ m, then in powder, add oxidation resistant organic additive to stir 30-90 minute, described oxidation resistant organic additive is by the organic substance containing electron donating group, borate and gasoline composition, organic volume ratio containing electron donating group is 10-80%, the volume ratio of borate is 2-75%, the volume ratio of gasoline is 10-80%, the described organic substance composition containing electron donating group is for containing anilino-, alkyl, amino, methoxyl group, a kind of or two kinds and the above mixture of hydroxyl, the addition of described anti-oxidant auxiliary agent is the 0.02%-0.04% of powder percentage by weight,

S3: moulding: the powder being stirred is put into moulding press mould and add magnetic field and be orientated, compressing after orientation, demagnetization Vacuum Package, take out after the green compact of Vacuum Package are put into isostatic pressing machine and pressurizeed 100-250Mpa, pressurize 2-6 minute;

S4: sintering: the green compact that obtain after step S3 moulding are put into sintering furnace sintering 4-6 hour at the temperature of 1060 DEG C-1150 DEG C, and air-cooled after tempering 1-2 hour at 800-900 DEG C, within tempering 3-5 hour, take out after the green compact after air-cooled are warming up to 500-600 DEG C again and obtain finished product.

2. the preparation method of the low weightless neodymium-iron-boron magnetic material of the compound interpolation of a titanium zirconium gallium, it is characterized in that: the component of described neodymium-iron-boron magnetic material and mass percent are: Nd:28.0%, B:1.0%, Dy:3.0%, Al:0.5%, Zr:0.2%, Ti:0.2%, Co:0.5%, Cu:0.1%, Ga:0.2%, surplus is Fe; Described preparation method comprises the following steps:

S1: melting: by component and the mass percent proportioning raw material of described neodymium-iron-boron magnetic material, and this raw material is put into vacuum spun furnace, when being evacuated to 3-8Pa, the air of vacuum spun furnace heats melting until temperature is closed vacuum valve while being warming up to 950-1100 DEG C, toward being filled with argon gas in vacuum spun furnace until in vacuum spun furnace pressure reach and be warming up to 1450 DEG C-1490 DEG C after 0.4-0.6MPa raw material is melted completely, after fusing, pour into the rejection tablet that thickness is 0.1mm-0.5mm completely;

S2: powder process: the rejection tablet that step S1 is obtained is inserted in hydrogen crushing furnace, in hydrogen crushing furnace, pass into hydrogen until furnace pressure is closed hydrogen valve after reaching 0.1-0.5Mpa, dehydrogenase 13-6 hour after hydrogen crushing furnace is warming up to 550 DEG C-650 DEG C, rejection tablet after dehydrogenation being put into airflow milling powder process and control powder particles is 3-6 μ m, then in powder, add oxidation resistant organic additive to stir 30-90 minute, described oxidation resistant organic additive is by the organic substance containing electron donating group, borate and gasoline composition, organic volume ratio containing electron donating group is 10-80%, the volume ratio of borate is 2-75%, the volume ratio of gasoline is 10-80%, the described organic substance composition containing electron donating group is for containing anilino-, alkyl, amino, methoxyl group, a kind of or two kinds and the above mixture of hydroxyl, the addition of described anti-oxidant auxiliary agent is the 0.02%-0.04% of powder percentage by weight,

S3: moulding: the powder being stirred is put into moulding press mould and add magnetic field and be orientated, compressing after orientation, demagnetization Vacuum Package, take out after the green compact of Vacuum Package are put into isostatic pressing machine and pressurizeed 100-250Mpa, pressurize 2-6 minute;

S4: sintering: the green compact that obtain after step S3 moulding are put into sintering furnace sintering 4-6 hour at the temperature of 1060 DEG C-1150 DEG C, and air-cooled after tempering 1-2 hour at 800-900 DEG C, within tempering 3-5 hour, take out after the green compact after air-cooled are warming up to 500-600 DEG C again and obtain finished product.