CN103757586A - Method of infiltrating metal infiltrating agent to cerium-containing neodymium iron boron magnetic material - Google Patents

Abstract

The invention discloses a method for doping a metallizing agent containing cerium-containing NdFeB magnetic material. By uniformly mixing R _x TM _1-x metallizing agent and cerium-containing NdFeB magnetic material, under certain negative pressure conditions Under heating, the heavy rare earth and its alloy elements of the metal infiltrant infiltrate into the surface of the cerium-containing NdFeB magnetic material and its grain boundary. In R _x TM _1-x , R represents one of Dy, Tb, and Ho elements or Several, TM is one or more of Ga, Co, Cu, Nb, Al, Zr elements, among which Dy, Tb, Ho elements and Ce, Nd in the hard magnetic main phase of cerium-containing NdFeB magnetic materials, Pr, Gd, etc. undergo substitution reactions, and the alloying elements Co, Al, etc. in the metallization agent replace the iron in the hard magnetic main phase, which can increase the coercive force of cerium-containing NdFeB; infiltration of dysprosium, terbium and their alloys The cerium-containing NdFeB magnetic material after the elements can be prepared through the dual main phase alloy process to prepare cerium-containing sintered NdFeB magnets that save Nd, Pr, Dy, Tb, and Ho elements and have high coercive force and corrosion resistance.

Description

A kind of method that the cerium-containing neodymium iron boron magnetic material is doped with metal infiltration agent

technical field

The invention belongs to the field of permanent magnet materials, in particular to a method for doping a cerium-containing neodymium-iron-boron magnetic material with a metallization agent.

Background technique

As an important part of the new material industry, rare earth permanent magnet materials are widely used in energy, transportation, machinery, medical, IT, home appliances and other industries, such as manufacturing various permanent magnet motors, vibration motors, permanent magnet instruments, electronics industry, nuclear magnetic resonance Devices, audio equipment and magnetic therapy equipment, etc., its products involve many fields of the national economy.

At present, the rare earth raw materials used to prepare NdFeB rare earth permanent magnet materials are mainly neodymium, praseodymium, dysprosium, terbium, etc. With the increasing use of NdFeB rare earth permanent magnet materials, rare earth metals such as neodymium, praseodymium, dysprosium, and terbium have become scarce resources, and it is urgent to find rare earth metals that can replace these scarce resources.

In rare earth ores, the distribution of Ce is much higher than that of Nd and Pr, and the price is low. However, the magnetic moment Js and anisotropy field H _A of Ce ₂ Fe ₁₄ B are much lower than those of Nd ₂ Fe ₁₄ B. Ce ₂ Fe ₁₄ B magnets prepared by traditional preparation methods cannot meet the performance requirements of users.

In 1990, OtsukiE and others proposed the double alloy method at the International Rare Earth Permanent Magnet and Application Conference held in Pittsburgh, that is, the alloy is smelted according to the proportion of the main phase, which is called the first alloy, and then according to the neodymium-rich phase and boron-rich phase The second alloy is smelted according to the composition of the grain boundary phase of the phase composition; the two alloys can be smelted by the vacuum quick-setting process respectively, and mixed in a certain proportion after smelting, and the subsequent process is the same as other processes. In order to improve the coercive force of the magnet, some people mainly use Dy and Tb as the rare earth in the second phase alloy.

In 2003, Machida et al. from Osaka University bombarded the heavy rare earths Dy and Tb as targets by sputtering to cover the surface of the magnet, and then carried out diffusion heat treatment and tempering. Finally, the residual magnetism was basically not reduced, and the rectification A magnet with increased coercive force.

Due to the difficulty in applying the sputtering method to mass production, in 2005, Nakamura Moto and others from Shin-Etsu Corporation developed a dip-coating method for grain boundary thermal diffusion of heavy rare earths. The heavy rare earth Dv and Tb compounds are attached to the surface of the sintered magnet by immersing in the solution, followed by heat diffusion and tempering. They found that the Dy diffusion increased the coercive force by 3.14-5.02kOe, and the Tb diffusion increased the coercive force by 8.16-10.0kOe.

In June 2008, Hitachi Metals announced that the developed heavy rare earth metal vapor deposition diffusion method had successfully increased the intrinsic coercive force by 4.02kOe under the same remanence conditions, and the remanence increased by 0.4kGs under the same coercive force conditions; 2009 In September 2009, ULVAC stated that using its ultra-high vacuum Dy sublimation technology to manufacture Nd-based magnets can greatly save Dy usage (up to 80% of Dy can be saved).

Chinese patent ZL200610089124.7 discloses that Yue Ming et al. from Beijing University of Technology use nano Dy and Tb powder as the second phase, and mix it with the first phase to produce high coercivity NdFeB technology. Under the same conditions, the amount of heavy rare earth is saved.

The patent application whose publication number is CN102347126A discloses the use of a metal infiltrant with a composition of Ra-Al or Ra-Al-X (Ra represents Dy or Tb; X represents one or more of Co, Cu, Ga, Zr elements) It is applied to the surface of the alloy sheet, and then heated and infiltrated into the grain boundary of the NdFeB quick-setting alloy sheet to obtain the effect of saving the heavy rare earth Dy or Tb.

The above documents and patents related to the hard magnetic phase of dysprosium and terbium technical objects are (Nd, Pr, Dy, Tb, Ho, Gd) FeB, and there is no mention of cerium-containing neodymium iron boron, and the correction of cerium-containing neodymium iron boron. The coercive force is low, and the amount of Nd, Pr and heavy rare earth is more, and the magnet made by this material has poor comprehensive performance.

Contents of the invention

The purpose of the present invention is to aim at some defects of cerium-containing NdFeB magnetic materials, and provide a method for doping cerium-containing NdFeB magnetic materials with a metallization agent, which can improve the coercive force of the main phase of cerium-containing NdFeB magnetic powder, Significantly reduce the amount of Nd, Pr and heavy rare earth.

In order to solve the above technical problems, the invention provides a method for doping a cerium-containing NdFeB magnetic material with a metallizing agent, comprising the following steps:

1) The metal infiltration agent alloy melt whose composition is R _x TM _1-x is made into powder, wherein R is one or more elements of Dy, Tb, and Ho, and TM is Ga, Co, Cu, Nb, Al , one or more of Zr elements, x is the weight percentage content of elements, and 40%≤x≤92%;

2) Mix the metallizing agent obtained in step 1) with the cerium-containing NdFeB magnetic material evenly, put it into a vacuum furnace, evacuate and preheat when the vacuum degree reaches above 10 ^-2 Pa, wherein the metallizing agent The ratio to NdFeB containing cerium is ≤10%;

3) When the vacuum degree reaches above 10 ^-2 Pa again, heat up to 550~650°C, and after the vacuum degree is stable above 10 ^-2 Pa, fill it with hydrogen or inert gas to -0.04~-0.08MPa;

4) Raise the temperature and keep it at 700-900°C for 3-10 hours, while maintaining the vacuum in the furnace at -0.04~-0.08MPa, doping Dy, Tb, Ho and other alloying elements of the metal infiltrant ;

The treatment of the cerium-containing neodymium-iron-boron magnetic material doped with a metallization agent is completed through the above steps.

The composition of the cerium-containing NdFeB magnetic material is (Ce _η Re _ζ RE _1-η-ζ ) _α Fe _100-α-β-γ B _β TM _γ , wherein Re is Dy, Tb, Ho element One or more of elements, RE is one or more of Nd, Pr, Gd elements, TM is one or more of Ga, Co, Cu, Nb, Al, Zr elements, η, ζ, α , β, γ are the weight percent content of each element, 0.1≤η≤0.8, 0≤ζ≤2%, 29≤α≤33, 0.8≤β≤1.4, 0.5≤γ≤3.6.

When the alloy melt is made into metal infiltration agent powder in step 1, under the protection of an inert gas atmosphere, the R _x TM _1-x alloy melt is quickly solidified by a water-cooled copper roller to form a quick-setting sheet with a thickness of less than 0.5mm, and then Metal infiltration agents with a particle size of less than 3 μm are made by hydrogen breaking and jet milling; or the R _x TM _1-x alloy melt is subjected to rapid solidification on a high-speed rotating disc and jet milling to make a metal infiltration agent with a particle size of less than 3 μm under the protection of an inert gas atmosphere. metal penetration agent.

The cerium-containing NdFeB magnetic material is a cerium-containing NdFeB quick-setting sheet or its hydrogen broken powder.

The magnetic material obtained by the above method is used as the second main phase, and the cerium-free NdFeB magnetic material is used as the first main phase. The two main phases are made into powder by hydrogen breaking and jet milling, and then double main phase is used The phase alloy method mixes the two main phase powders uniformly, presses and sinters to obtain a cerium-containing NdFeB magnet. The obtained magnet can save Nd, Pr, Dy, and Tb elements, has high coercive force and corrosion resistance, and has good comprehensive performance.

The present invention aims at the shortcoming of the low coercive force of cerium-containing NdFeB, through the method of doping the metallization agent of heavy rare earth and its alloy elements, the R _x TM _1-x metallization agent is combined with the cerium-containing NdFeB The quick-setting alloy flakes or their hydrogen broken powders are mixed evenly, heated under certain negative pressure conditions, so that the heavy rare earth and its alloy elements penetrate into the surface and grain boundary of the cerium-containing NdFeB quick-setting alloy flakes or their hydrogen broken powders Among them, Dy, Tb, Ho elements have substitution reactions with Ce, Nd, Pr, Gd, etc. in the cerium-containing NdFeB quick-setting alloy sheet or its hydrogen-breaking hard magnetic main phase, and at the same time R _x TM _1-x metal The alloying elements Co, Al, etc. in the infiltration agent replace the iron in the hard magnetic main phase, which can increase the coercive force of the cerium-containing NdFeB, and significantly reduce the amount of Nd, Pr and heavy rare earth. The cerium-containing NdFeB magnetic material infiltrated with dysprosium, terbium and its alloy elements can be used to prepare cerium-containing sintered materials that save Nd, Pr, Dy, and Tb elements, and have high coercive force and corrosion resistance. NdFeB magnets.

Detailed ways

The present invention will be further described below in conjunction with the examples, but the protection scope of the present invention is not limited to the scope expressed in the examples.

Example 1:

The dual-main-phase alloy method is adopted, and the first main phase is hydrogen-broken and air-ground Nd ₃₀ Fe _bal B ₁ TM _0.8 with a particle size of 0.35 μm, and the mass percentage is 20%.

(Ce _0.8 Nd _0.2 ) ₃₀ Fe _bal B ₁ TM _0.8 quick-setting sheet with a thickness of 0.3 mm was used, and Dy ₈₀ Al ₂₀ with a particle size of less than 2 μm was used as the metallization agent. Mix the metallizing agent of Dy ₈₀ Al ₂₀ with (Ce _0.8 Nd _0.2 ) ₃₀ Fe _bal B ₁ TM _0.8 evenly in a ratio of 1.5% by weight of the metallizing agent to the quick-setting sheet, place in a vacuum furnace, and evacuate to When the vacuum is above 10 ^-2 Pa, preheat with low power. When the vacuum degree reaches above 10 ^-2 Pa again, increase the power and heat up to about 650°C. After the vacuum degree is stable above 10 ^-2 Pa, fill high-purity hydrogen to -0.06MPa; increase the power to keep the temperature at 800°C for 6 hours, and at the same time maintain the vacuum in the furnace at -0.04MPa to infiltrate dysprosium and aluminum, and then undergo hydrogen breakdown and jet milling to make a powder with a particle size of 0.30μm. The mass percentage of the second main phase is 80%.

Mix the two main phase powders uniformly, press and sinter to obtain a cerium-containing NdFeB magnet with a nominal composition of (Ce ₀₆₁₅₄ Nd ₀₃₄₆₂ Dy _0.0384 ) ₃₀ Fe _bal B ₁ TM _0.8 .

The relevant magnetic performance parameters of the magnet are shown in Table 1:

Table 1

Nominal composition (wt.%) B _r /kGs H _cj /kOe (BH) _m /MGOe (Ce _0.6154 Nd _0.3462 Dy _0.0384 ) ₃₀ Fe _bal B ₁ TM _0.8 12.3 14.1 35.4

Example 2:

Using the dual main phase alloy method, the first main phase is broken by hydrogen, and the Nd ₃₀ Fe _bal B ₁ TM _0.8 with a particle size of 0.30 μm is air-fed, and the mass percentage is 40%;

(Ce _0.6 Nd _0.4 ) ₃₀ Fe _bal B ₁ TM _0.8 (wt%) quick-setting sheet with a thickness of 0.3 mm is used, and Dy ₉₁ Al ₉ with a particle size of less than 2 μm is used as a metallization agent. Mix the metallizing agent of Dy ₉₁ Al ₉ with (Ce _0.6 Nd _0.4 ) ₃₀ Fe _bal B ₁ TM _0.8 (wt%) uniformly in a ratio of 2% by weight of the metallizing agent and the NdFeB quick-setting sheet, place In the vacuum furnace, preheat with low power when the vacuum reaches above 10 ^-2 Pa. When the vacuum degree reaches above 10 ^-2 Pa again, increase the power and heat up to about 600°C. After the vacuum degree is stable above 10 ^-2 Pa , fill the mixed gas of H ₂ and argon to -0.06MPa; increase the power to keep the temperature at 880°C for 4 hours, and maintain the vacuum in the furnace at -0.04MPa at the same time, carry out dysprosium and aluminum infiltration, and then break through hydrogen, and the air flow Grinding into a powder with a particle size of 0.35 μm constitutes the second main phase, and the mass percentages are 60% respectively.

The two main phase powders were uniformly mixed, pressed and sintered to obtain a magnet with a nominal composition of (Ce _0.3374 Nd _0.6175 Dy _0.0351 ) ₃₀ Fe _bal B ₁ TM _0.8 (wt%).

The relevant magnetic performance parameters of the magnet are shown in Table 2:

Table 2

Nominal composition (wt.%) B _r /kGs H _cj /kOe (BH) _m /MGOe (Ce _0.3374 Nd ₀₆₁₇₅ Dy _0.0351 ) ₃₀ Fe _bal B ₁ TM _0.8 13.9 14.2 45.2

Example 3:

Using the dual main phase alloy method, the first main phase is broken by hydrogen, and the Nd ₃₀ Fe _bal B ₁ TM _0.8 with a particle size of 0.35 μm is air-fed, and the mass percentage is 50%;

(Ce _0.5 Nd _0.5 ) ₃₀ Fe _bal B ₁ TM _0.8 (wt%) quick-setting sheet with a thickness of 0.35 mm is used, and Dy ₈₀ Al ₁₀ Cu ₁₀ with a particle size of less than 2 μm is used as the metallization agent. Mix the metal infiltration agent and the cerium-containing NdFeB quick-setting sheet at a weight ratio of 3%, and mix them evenly, place them in a vacuum furnace, preheat with low power when the vacuum reaches 10 ^-2 Pa, and wait until the vacuum degree After stabilizing above 10 ^-2 pa, increase the power to raise the temperature to about 550°C and fill it with high-purity argon to -0.07MPa; increase the power to keep the temperature at 780°C for 10 hours while maintaining the vacuum in the furnace at -0.04MPa , infiltrate dysprosium and aluminum, and then undergo hydrogen breakdown and jet milling to make a powder with a particle size of 0.25 μm, which constitutes the second main phase, and the mass percentages are 50% respectively.

The two main phase powders were uniformly mixed, pressed and sintered to obtain a magnet with a nominal composition of (Ce _0.2404 Nd _0.7211 Dy _0.0385 ) ₃₀ Fe _bal B ₁ TM _0.8 (wt%).

The relevant magnetic performance parameters of the magnet are shown in Table 3:

table 3

Nominal composition (wt.%) B _r /kGs H _cj /kOe (BH) _m /MGOe (Ce _0.2404 Nd _0.7211 Dy _0.0385 ) ₃₀ Fe _bal B ₁ TM _0.8 14 14.3 46

It can be seen from the above examples that after the cerium-containing NdFeB quick-setting sheet and its hydrogen breaking powder are doped with heavy rare earth and alloy elements, the magnetic material is made by the dual-main-phase alloy method, which significantly reduces Nd, Pr and the amount of heavy rare earth.

The above-mentioned embodiments only express the preferred implementation of the present invention, and the description thereof is relatively specific and detailed, but should not be construed as limiting the patent scope of the present invention. It should be noted that those skilled in the art can make several modifications, improvements and substitutions without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (8)

1. a method of mixing metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium, is characterized in that: comprise the following steps:

1) by composition, be R _xtM _1-xalloy melt make metal penetrating agent powder, wherein R is one or more of Dy, Tb, Ho element, TM is one or more in Ga, Co, Cu, Nb, Al, Zr element, the weight percent content that x is element, and 40%≤x≤92%;

2) by step 1) metal penetrating agent of gained mixes with the neodymium iron boron magnetic material containing cerium, puts into vacuum oven, and vacuumize and treat that vacuum tightness reaches 10 ^-2when pa is above, carry out preheating, wherein, metal penetrating agent and ratio≤10% that contains the neodymium iron boron of cerium;

3) treat that vacuum tightness reaches 10 again ^-2more than Pa, be warmed up to 550～650 ℃, treat that vacustat is 10 ^-2after Pa is above, be filled with hydrogen or rare gas element to-0.04～-0.08MPa;

4) rising temperature also maintains the temperature at 700-900 ℃, and the time is 3-10 hour, maintains vacuum tightness in stove simultaneously and, at-0.04～-0.08MPa, mixes and ooze Dy, Tb, Ho;

By above-mentioned steps, complete the processing of mixing metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium.

2. the method for mixing metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium according to claim 1, is characterized in that: the composition of the described neodymium iron boron magnetic material containing cerium is (Ce _ηre _ζrE _1-η-ζ) _αfe _{100-alpha-beta-γ}b _βtM _γwherein Re is Dy, one or more in Tb, Ho element, RE is one or more in Nd, Pr, Gd element, TM is one or more in Ga, Co, Cu, Nb, Al, Zr element, the weight percent content that η, ζ, α, β, γ are each element, 0.1≤η≤0.8,0≤ζ≤2%, 29≤α≤33,0.8≤β≤1.4,0.5≤γ≤3.6.

3. the method for mixing metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium according to claim 1, is characterized in that: in step 1 by R _xtM _1-xwhen alloy melt is made metal penetrating agent, first adopt the rapid hardening of water-cooled copper roller to make the rapid-hardening flake that thickness is less than 0.5mm, by hydrogen, broken and airflow milling is made powder; Or directly through High Speed Rotating Disks At Elevated soon solidifying and airflow milling make metal penetrating agent powder.

4. the method for mixing metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium according to claim 1, is characterized in that: the granularity of described metal penetrating agent powder is less than 3 μ m.

5. the method for mixing metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium according to claim 1, is characterized in that: described metal penetrating agent and ratio≤10% that contains the neodymium iron boron of cerium.

6. according to the method for mixing metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium one of claim 1-5 Suo Shu, it is characterized in that: the described neodymium-iron-boron magnetic material containing cerium is the neodymium iron boron rapid-hardening flake containing cerium or the broken powder of its hydrogen.

7. the material that adopts the described method of one of claim 1-6 to process prepare containing cerium neodymium iron boron magnetic body, it is characterized in that: take by mix the material of the method processing of metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium is the second principal phase, the neodymium-iron-boron magnetic material of take not containing cerium is the first principal phase, two principal phases are broken through hydrogen, airflow milling is made powder, then adopt two main-phase alloy methods by two principal phase powders mix, compacting, sintering must contain cerium neodymium iron boron magnetic body.

8. the method for mixing metallic cementation penetration enhancer containing the neodymium-iron-boron magnetic material of cerium according to claim 1, is characterized in that: in step 4) in can also mix other alloying elements of metallic cementation penetration enhancer.