CN106252012A - A kind of sintering method of neodymium iron boron magnetic body - Google Patents

A kind of sintering method of neodymium iron boron magnetic body Download PDF

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CN106252012A
CN106252012A CN201610757793.0A CN201610757793A CN106252012A CN 106252012 A CN106252012 A CN 106252012A CN 201610757793 A CN201610757793 A CN 201610757793A CN 106252012 A CN106252012 A CN 106252012A
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sintering
fired
temperature
constant temperature
stage
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CN106252012B (en
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余远
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Jingci Material Technology Co Ltd
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Jingci Material Technology Co Ltd
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F1/00—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties
    • H01F1/01—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials
    • H01F1/03—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity
    • H01F1/032—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials
    • H01F1/04—Magnets or magnetic bodies characterised by the magnetic materials therefor; Selection of materials for their magnetic properties of inorganic materials characterised by their coercivity of hard-magnetic materials metals or alloys
    • H01F1/047—Alloys characterised by their composition
    • H01F1/053—Alloys characterised by their composition containing rare earth metals
    • H01F1/055—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5
    • H01F1/057—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B
    • H01F1/0571—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes
    • H01F1/0575—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together
    • H01F1/0577—Alloys characterised by their composition containing rare earth metals and magnetic transition metals, e.g. SmCo5 and IIIa elements, e.g. Nd2Fe14B in the form of particles, e.g. rapid quenched powders or ribbon flakes pressed, sintered or bonded together sintered
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1017—Multiple heating or additional steps
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10—Sintering only
    • B22F3/1017—Multiple heating or additional steps
    • B22F3/1028—Controlled cooling
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/02—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets
    • H01F41/0253—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for manufacturing cores, coils, or magnets for manufacturing permanent magnets

Abstract

The invention provides the sintering method of a kind of neodymium iron boron magnetic body, the present invention multiple steps in neodymium-iron-boron production procedure are analyzed, start with from the sintering process of neodymium iron boron, the method using multi-steps sintering, can significantly prevent crystal grain from growing up, acquisition crystal grain is tiny, the magnet that density is homogeneous, thus significantly improve the magnetic property of magnet, neodymium iron boron magnetic body especially for low content of rare earth, while reducing heavy rare earth content the most in the industry, also can reduce granularity and the process oxygen content of neodymium iron boron powder body, cause the problem that abnormal grain! growth and the remanent magnetism of magnet and squareness do not reach requirement.The method that the present invention provides can obtain crystal grain without exception and grow up, and has the neodymium iron boron magnetic body of more preferable remanent magnetism and squareness.

Description

A kind of sintering method of neodymium iron boron magnetic body
Technical field
The invention belongs to magnet preparing technical field, particularly relate to the sintering method of a kind of neodymium iron boron magnetic body.
Background technology
Hard magnetic body i.e. permanent magnet, it is possible to the long-term magnet keeping its magnetic, is difficult to loss of excitation, is not easy to be magnetized.Thus, nothing Opinion is in commercial production or in daily life, one of muscle material that hard magnetic body is the most frequently used.Hard magnetic body can be divided into natural Magnet and artificial magnet, artificial magnet refers to can be reached and natural magnet (magnet) phase by the alloy of synthesis different materials Same effect, but also magnetic force can be improved.The sixties in 20th century, the appearance of rare earth permanent magnet, then the application for magnet opens One New Times, first generation samarium cobalt permanent magnet SmCo5, second filial generation precipitation hardenable samarium cobalt permanent magnet Sm2Co17, up to now, develop into Third generation Nd-Fe-B permanent magnet material (NdFeB).Although at present ferrimagnet remains the permanent magnet material that consumption is maximum, but neodymium ferrum The output value of boron magnet has substantially exceeded ferrite permanent-magnet materials, has evolved into a big industry.
Neodymium iron boron magnetic body is also referred to as neodymium magnet (Neodymium magnet), and its chemical formula is Nd2Fe14B, is a kind of artificial Permanent magnet, be also the permanent magnet so far with the strongest magnetic force, its maximum magnetic energy product (BH) max exceeds ferrite 10 More than Bei, when naked magnetic, its magnetic force can reach 3500 Gauss.The advantage of neodymium iron boron magnetic body is that cost performance is high, body Long-pending little, lightweight, good mechanical property and the feature such as magnetic is strong, the advantage of such high-energy-density makes Nd-Fe-B permanent magnet material Modern industry and electronic technology obtain a wide range of applications, is described as magnetic king in magnetics circle.Thus, the system of neodymium iron boron magnetic body The focus that standby and extension always gives more sustained attention in the industry.
At present, industry makes Nd-Fe-B permanent magnet material frequently with sintering process, as Wang Wei waits at " key process parameter and alloy The element impact on Sintered NdFeB magnetic property Yu mechanical property " in disclose and use sintering process to manufacture Nd-Fe-B permanent magnet material Technological process, generally comprises that dispensing, melting, steel ingot be broken, powder process, vacuum preserve micropowder, powder orientation is compressing and true The steps such as empty sintering.
Along with the development of the association area such as air-conditioning, electric automobile, more and more higher to the demand of neodymium iron boron magnetic body, to its performance Requirement significantly improves.Adding rare earth element in magnet is a kind of Main Means improving magnetic property, but along with the valency of heavy rare earth Lattice rise steadily, and industry, pursuing high performance while, needs again to consider cost factor, reduces the usage amount of heavy rare earth, and right For Sintered NdFeB magnet, the usage amount of heavy rare earth reduces, it will usually causes the abnormal growth of crystal grain, and then affects magnetic Energy.
Therefore, how in the case of relatively low rare earth adding quantity, the effective size controlling magnet crystal grain, it is thus achieved that more preferably Magnetic property, it has also become the most forward-looking neodymium iron boron magnetic body production firm and the focus of research worker extensive concern.
Summary of the invention
In view of this, the technical problem to be solved in the present invention is to provide the sintering method of a kind of neodymium iron boron magnetic body, this The sintering method of bright offer can significantly prevent crystal grain from growing up, it is possible to obtains crystal grain tiny, and the neodymium iron boron magnetic body that density is homogeneous enters And can effectively improve the magnetic property of magnet, especially for the neodymium iron boron magnetic body of low content of rare earth.
The invention provides the sintering method of a kind of neodymium iron boron magnetic body, comprise the following steps:
A) under conditions of vacuum or protective gas, neodymium iron boron magnetic body pressed compact is fired through primary stage ladder-elevating temperature After, obtain just section sintering intermediate；
B) first section sintering intermediate above-mentioned steps obtained, carries out after first stage intensification constant temperature fires, obtaining one section Sintering intermediate；
C) one-stage sintering intermediate above-mentioned steps obtained, carries out after second stage intensification constant temperature fires, obtaining two-stage nitration Sintering intermediate；
D) bis sintering intermediate above-mentioned steps obtained, after carrying out phase III cooling, obtains in the middle of three-stage sintering Body；
E) three-stage sintering intermediate above-mentioned steps obtained, carries out after fourth stage intensification constant temperature fires, obtaining neodymium ferrum Boron magnet blank.
Preferably, described primary stage ladder-elevating temperature is fired and is included that defat is fired, degassing for the first time is fired and second successively Secondary degassing is fired.
Preferably, the heating rate that described defat is fired is 5～6 DEG C/min；The thermostat temperature that described defat is fired is 200 ～300 DEG C；The constant temperature time that described defat is fired is 1～2h；
The heating rate that the degassing of described first time is fired is 5～6 DEG C/min；The thermostat temperature that the degassing of described first time is fired It it is 500～700 DEG C；The constant temperature time that the degassing of described first time is fired is 2～3h；
The heating rate that the degassing of described second time is fired is 4～5 DEG C/min；The temperature that the degassing of described second time is fired is 800～900 DEG C；The constant temperature time that the degassing of described second time is fired is 3～5h.
Preferably, the heating rate that described first stage intensification constant temperature is fired is 2～3 DEG C/min；
The thermostat temperature that described first stage intensification constant temperature is fired is (sintering temperature-20 DEG C)；
The constant temperature time that described first stage intensification constant temperature is fired is 0～1h；
The sintering temperature of described neodymium iron boron magnetic body is 1000～1100 DEG C.
Preferably, the heating rate that described second stage intensification constant temperature is fired is 2～3 DEG C/min；
The thermostat temperature that described second stage intensification constant temperature is fired is sintering temperature；
The constant temperature time that described second stage intensification constant temperature is fired is 3～6h.
Preferably, the mode of cooling of described phase III is natural cooling；
Temperature after the cooling of described phase III is 700～800 DEG C.
Preferably, the heating rate that described fourth stage intensification constant temperature is fired is 5～7 DEG C/min；
The thermostat temperature that described fourth stage intensification constant temperature is fired is sintering temperature～(sintering temperature+20 DEG C)；
The constant temperature time that described fourth stage intensification constant temperature is fired is 5～8h.
Preferably, described fourth stage intensification constant temperature also includes cooling step after firing；
Described cooling step be specially the most air-cooled under conditions of nitrogen or noble gas, the speed of described cooling be 0.1～ 0.5℃/min。
Preferably, tempering step is also included after described cooling step；
Described tempering step includes one-level tempering and second annealing；
The temperature of described one-level tempering is 850～950 DEG C；The time of described one-level tempering is 4～6h；
The temperature of described second annealing is 460～600 DEG C；The time of described second annealing is 3～6h.
Present invention also offers a kind of neodymium iron boron magnetic body, neodymium iron boron magnetic body pressed compact obtain after multi-steps sintering；
The hop count of described segmentation is four sections or five sections；
Described neodymium iron boron magnetic body raw material, composition includes by mass percentage: Pr-Nd:28%～33%；Dy:0～10%； Tb:0～10%；Nb:0～5%；Al:0～1%；B:0.5%～2.0%；Cu:0～1%；Co:0～3%；Ga:0～2%； Gd:0～2%；Ho:0～2%；Zr:0～2%；Surplus is Fe.
The invention provides the sintering method of a kind of neodymium iron boron magnetic body, comprise the following steps, first in vacuum or protectiveness Under conditions of gas, by neodymium iron boron magnetic body pressed compact after ladder-elevating temperature is fired through the primary stage, obtain just section sintering intermediate；So After first section sintering intermediate that above-mentioned steps is obtained, carry out after first stage intensification constant temperature fires, obtaining in the middle of one-stage sintering Body；One-stage sintering intermediate above-mentioned steps obtained again, carries out after second stage intensification constant temperature fires, obtaining in bis sintering Mesosome；Bis sintering intermediate above-mentioned steps obtained subsequently, after carrying out phase III cooling, obtains in the middle of three-stage sintering Body；The three-stage sintering intermediate finally above-mentioned steps obtained, carries out after fourth stage intensification constant temperature fires, obtaining neodymium-iron-boron Chaeta base.Compared with prior art, the present invention is directed to existing sintering method and there is abnormal grain growth and magnet density difference Big defect, and then affect the problem of blank concordance and magnetic property, multiple in neodymium-iron-boron production procedure of the present invention Step is analyzed, and starts with from the sintering process of neodymium iron boron, the sintering method using the present invention to provide, and can significantly prevent crystalline substance Grain length is big, it is thus achieved that crystal grain is tiny, the magnet that density is homogeneous, thus significantly improves the magnetic property of magnet, especially for low dilute The neodymium iron boron magnetic body of soil content, reduces while heavy rare earth content the most in the industry, also can reduce the granularity of neodymium iron boron powder body with And process oxygen content, cause the problem that abnormal grain! growth and the remanent magnetism of magnet and squareness do not reach requirement；The present invention carries The method of confession can obtain crystal grain without exception and grow up, and has the neodymium iron boron blank of more preferable remanent magnetism and squareness.
Test result indicate that, the sintering method of the neodymium iron boron magnetic body that the present invention provides, when producing formula of the same race, crystallite dimension Uniformly, crystal grain without exception is grown up, and compares conventional method squareness and can improve 2%～8%, and coercivity can improve 1%～5%.
Accompanying drawing explanation
The sintering curre figure of the multi-steps sintering method that Fig. 1 provides for the present invention；
Fig. 2 is the metallograph of the neodymium iron boron magnetic body blank of the embodiment of the present invention 1 preparation；
Fig. 3 is the metallograph of the neodymium iron boron magnetic body blank of the embodiment of the present invention 2 preparation；
Fig. 4 is the metallograph of the neodymium iron boron magnetic body blank of the embodiment of the present invention 3 preparation；
Fig. 5 is the metallograph of the neodymium iron boron magnetic body blank of comparative example 2 of the present invention preparation.
Detailed description of the invention
In order to be further appreciated by the present invention, below in conjunction with embodiment, the preferred embodiment of the invention is described, but Should be appreciated that these descriptions are intended merely to further illustrate the features and advantages of the present invention rather than to invention claim Limit.
The all raw materials of the present invention, are not particularly limited its source, that commercially buy or according to people in the art Prepared by the conventional method known to Yuan.
The all raw materials of the present invention, are not particularly limited its purity, present invention preferably employs analytical pure or sintered NdFeB The conventional purity that field of magnets uses.
The invention provides the sintering method of a kind of neodymium iron boron magnetic body, comprise the following steps:
A) under conditions of vacuum or protective gas, neodymium iron boron magnetic body pressed compact is fired through primary stage ladder-elevating temperature After, obtain just section sintering intermediate；
B) first section sintering intermediate above-mentioned steps obtained, carries out after first stage intensification constant temperature fires, obtaining one section Sintering intermediate；
C) one-stage sintering intermediate above-mentioned steps obtained, carries out after second stage intensification constant temperature fires, obtaining two-stage nitration Sintering intermediate；
D) bis sintering intermediate above-mentioned steps obtained, after carrying out phase III cooling, obtains in the middle of three-stage sintering Body；
E) three-stage sintering intermediate above-mentioned steps obtained, carries out after fourth stage intensification constant temperature fires, obtaining neodymium ferrum Boron magnet blank.
The present invention is first under conditions of vacuum or protective gas, by neodymium iron boron magnetic body pressed compact through primary stage ladder After intensification is fired, obtain just section sintering intermediate.
The sintering of described neodymium iron boron magnetic body is not particularly limited by the present invention, with neodymium iron boron well known to those skilled in the art The sintering concept of magnet, the present invention is preferably liquid-phase sintering or solid-phase sintering, more preferably liquid-phase sintering, more preferably will Loose being placed in material boat of the most compressing magnet pressed compact is fired in agglomerating plant.The present invention is to described neodymium-iron-boron The sintering temperature of body is not particularly limited, with the sintering temperature of neodymium iron boron magnetic body well known to those skilled in the art, ability Field technique personnel can select according to factors such as neodymium iron boron composition, powder size size and oxygen contents and adjust, the present invention The sintering temperature of described neodymium iron boron magnetic body is preferably 1000～1100 DEG C, more preferably 1020～1080 DEG C, and most preferably 1040 ～1060 DEG C.
The equipment of described sintering is not particularly limited by the present invention, with sintered NdFeB magnetic well known to those skilled in the art The equipment of body, the present invention is preferably vacuum sintering furnace.Temperature homogeneity in the equipment of described sintering is not had by the present invention Limit especially, with temperature well known to those skilled in the art all with property, the furnace temperature of vacuum sintering furnace of the present invention is uniform Property be preferably ± 5 DEG C, more preferably ± 4 DEG C, most preferably ± 3 DEG C；The Pressure Rise Rate of vacuum sintering furnace of the present invention is the least In equal to 0.6Pa/h, more preferably less than or equal to 0.5Pa/h, more preferably less than equal to 0.4Pa/h.The present invention is to described neodymium iron boron The source of magnet pressed compact is not particularly limited, with conventional production practices well known to those skilled in the art, art technology Personnel can select according to practical condition, prescription and properties of product and adjust, and present invention preferably comprises and join Material, melting, hydrogen explosion are broken, powder process and the main process such as orientation is compressing, obtain neodymium iron boron magnetic body pressed compact.The present invention is to described The density of neodymium iron boron magnetic body pressed compact is not particularly limited, with the density of pressed compact well known to those skilled in the art, this area Technical staff can require according to practical condition, product quality and product type selects or adjusts, and the present invention is Ensureing anticorrosion effect, the density of described pressed compact is preferably 3.0～5.8g/cm3, more preferably 3.1～5.6g/cm3, more preferably It is 3.2～5.4g/cm3, more preferably 3.3～5.3g/cm3, most preferably 3.5～5.0g/cm3。
The content of neodymium iron boron magnetic body pressed compact or blank is not particularly limited by the present invention, forms the most by mass percentage, Including Pr-Nd:28%～33%；Dy:0～10%；Tb:0～10%；Nb:0～5%；Al:0～1%；B:0.5%～ 2.0%；Cu:0～1%；Co:0～3%；Ga:0～2%；Gd:0～2%；Ho:0～2%；Zr:0～2%；Surplus is Fe.Its Described in the mass percentage content of Pr-Nd be preferably 29%～33%, more preferably 29%～32%, most preferably 29.5% ～31%；The mass percentage content of described Dy is preferably 1.0%～9.0%, more preferably 2.0%～8.0%, most preferably 3.0%～7.0%；The mass percentage content of described Tb is preferably 1.0%～9.0%, more preferably 2.0%～8.0%, It is preferably 3.0%～7.0%；The mass percentage content of described Nb be preferably 1.0%～4.0%, more preferably 1.5%～ 3.5%, most preferably 1.8%～3.2%；The mass percentage content of described Al is preferably 0.2%～0.8%, more preferably 0.3%～0.6%, most preferably 0.3%～0.5%；The mass percentage content of described B is preferably 0.8%～1%, more excellent Elect 0.85%～1.3% as, more preferably 0.9%～1.2%, most preferably 0.9%～1.1%；The percent mass of described Cu It is preferably 0.01%～0.8% than content, more preferably 0.02%～0.7%, most preferably 0.03%～0.6%；Described Co Mass percentage content be preferably 0.2%～2.0%, more preferably 0.3%～1.5%, most preferably 0.4%～1.2%； The mass percentage content of described Ga is preferably 0%～1.5%, more preferably 0.1%～1.2%, more preferably 0.15%～ 1.0%, most preferably 0.2%～0.9%；The mass percentage content of described Gd is preferably 0.3%～1.5%, more preferably 0.5%～1.2%, more preferably 0.7%～1.0%, most preferably 0.8%～0.9%；The mass percentage content of described Ho Be preferably 0.3%～1.5%, more preferably 0.5%～1.2%, more preferably 0.7%～1.0%, most preferably 0.8%～ 0.9%；The mass percentage content of described Zr is preferably 0%～1.5%, more preferably 0.1%～1.2%, more preferably 0.15%～1.0%, most preferably 0.2%～0.9%.
The condition of described vacuum or protective gas is not particularly limited by the present invention, with well known to those skilled in the art Conventional production practices, those skilled in the art can be carried out according to practical condition, prescription and properties of product Selecting and adjust, the present invention is more preferably vacuum；The pressure of described vacuum is not particularly limited by the present invention, with art technology The vacuum pressure of the Sintered NdFeB magnet known to personnel, the pressure of vacuum of the present invention is preferably less than equal to 0.5Pa, more preferably 0.01～0.45Pa, more preferably 0.1～0.4Pa, most preferably 0.25～0.35Pa.Of the present invention Protective gas is preferably noble gas and/or nitrogen, more preferably argon and/or nitrogen, most preferably argon or nitrogen.
Curve of firing during described multi-steps sintering is not particularly limited by the present invention, and those skilled in the art can root Selecting according to practical condition, prescription and properties of product and adjust, multi-steps sintering process of the present invention is preferred Including primary stage sintering (presintering), first paragraph sintering, second segment sintering, three-stage sintering and the 4th section of sintering, based on this Field common knowledge, primary stage sintering can be regarded as the stage of sintering process, then multi-steps sintering process of the present invention is Five sections of sintering, it is also possible to be not considered the stage of sintering process, then multi-steps sintering process of the present invention is then four sections of sintering.
Concrete steps and condition that described primary stage ladder-elevating temperature is fired by the present invention are not particularly limited, with this area The concrete steps fired of early stage of the neodymium iron boron magnetic body sintering known to technical staff and condition, those skilled in the art are permissible Selecting according to practical condition, prescription and properties of product and adjust, the present invention is to improve the performance of magnet, institute State primary stage ladder-elevating temperature to fire, i.e. presintering, include successively defat fire (defat platform, this stage can by pressed compact with Most of lipid of physical absorption is got rid of in gaseous form), for the first time degassing fire (the first degassing platform, the most fully row Except the gas of physical absorption, additionally rich neodymium starts liquefaction mutually) and second time degassing is fired, and (the second degassing platform, sufficiently gets rid of The gas of chemisorbed, makes rich neodymium the most fully liquefy, and blank drastically shrinks).
The actual conditions of described defat sintering procedure is not particularly limited by the present invention, with well known to those skilled in the art The actual conditions of skimming processes in magnet sintering process, those skilled in the art can be according to practical condition, quality Requiring and properties of product select and adjust, defat platform temperature of the present invention, the thermostat temperature that i.e. defat is fired is excellent Elect 200～300 DEG C as, more preferably 220～280 DEG C, most preferably 240～260 DEG C；The heating rate that described defat is fired is excellent Elect 5～6 DEG C/min, more preferably 5.2～5.8 DEG C/min, most preferably 5.4～5.6 DEG C/min as；The perseverance that described defat is fired The temperature time is preferably 1～2h, more preferably 1.2～1.8h, most preferably 1.4～1.6h.
The actual conditions that the degassing of described first time is fired by the present invention is not particularly limited, and knows with those skilled in the art Magnet sintering process in the actual conditions of degasification process, those skilled in the art can be according to practical condition, matter Amount requires and properties of product select and adjust, and the first degassing platform temperature of the present invention, degassing i.e. for the first time is fired Temperature be preferably 500～700 DEG C, more preferably 550～650 DEG C, most preferably 575～625 DEG C；The degassing of described first time is burnt The heating rate of system is preferably 5～6 DEG C/min, more preferably 5.2～5.8 DEG C/min, most preferably 5.4～5.6 DEG C/min；Institute State the constant temperature time fired that deaerates for the first time and be preferably 2～3h, more preferably 2.2～2.8h, most preferably 2.4～2.6h.
The actual conditions that the degassing of described second time is fired by the present invention is not particularly limited, and knows with those skilled in the art Magnet sintering process in the actual conditions of degasification process, those skilled in the art can be according to practical condition, matter Amount requires and properties of product select and adjust, and the second degassing platform temperature of the present invention, i.e. second time degassing is fired Temperature be preferably 800～900 DEG C, more preferably 820～880 DEG C, most preferably 840～860 DEG C；The degassing of described second time is burnt The heating rate of system is preferably 4～5 DEG C/min, more preferably 4.2～4.8 DEG C/min, most preferably 4.4～4.6 DEG C/min；Institute State the constant temperature time fired that deaerates for the second time and be preferably 3～5h, more preferably 3.5～4.5h, most preferably 3.8～4.2h.
First section that then above-mentioned steps is obtained by present invention sintering intermediate, carries out after first stage intensification constant temperature fires, Obtain one-stage sintering intermediate.
The parameter that described first stage intensification constant temperature is fired by the present invention is not particularly limited, and those skilled in the art are permissible Select according to practical condition, useful load, oxygen content and green compact size etc. or adjust, described first stage intensification constant temperature The heating rate fired is preferably 2～3 DEG C/min, more preferably 2.2～2.8 DEG C/min, most preferably 2.4～2.6 DEG C/min. The thermostat temperature that described first stage intensification constant temperature is fired by the present invention is not particularly limited, and those skilled in the art can basis Practical condition, useful load, oxygen content and green compact size etc. select or adjust, and the first stage of the present invention heats up permanent The thermostat temperature that temperature is fired is preferably (sintering temperature-20 DEG C), i.e. less than sintering temperature 20 DEG C, and i.e. 980～1080 DEG C, more preferably It is 985～1085 DEG C, most preferably 990～1090 DEG C.The constant temperature time that described first stage intensification constant temperature is fired by the present invention Being not particularly limited, those skilled in the art can be carried out according to practical condition, useful load, oxygen content and green compact size etc. Selecting or adjust, the constant temperature time that first stage intensification constant temperature of the present invention is fired is preferably 0～1h, more preferably≤1h, Most preferably 0.1～0.8h.
The present invention arranges first presintering platform before entering sintering temperature platform, the hair of all positions in can promoting stove Base, to the concordance of temperature, makes all of blank sintering more uniform.
The one-stage sintering intermediate that above-mentioned steps is obtained by the present invention again, carries out after second stage intensification constant temperature fires, To bis sintering intermediate.
The parameter that described second stage intensification constant temperature is fired by the present invention is not particularly limited, and those skilled in the art are permissible Select according to practical condition, useful load, oxygen content and green compact size etc. or adjust, described second stage intensification constant temperature The heating rate fired is preferably 2～3 DEG C/min, more preferably 2.2～2.8 DEG C/min, most preferably 2.4～2.6 DEG C/min. The thermostat temperature that described second stage intensification constant temperature is fired by the present invention is not particularly limited, and those skilled in the art can basis Practical condition, useful load, oxygen content and green compact size etc. select or adjust, and second stage of the present invention heats up permanent The thermostat temperature that temperature is fired is preferably sintering temperature, i.e. 1000～1100 DEG C, more preferably 1020～1080 DEG C, most preferably 1040～1060 DEG C.The constant temperature time that described second stage intensification constant temperature is fired by the present invention is not particularly limited, this area skill Art personnel can select according to practical condition, useful load, oxygen content and green compact size etc. or adjust, of the present invention The constant temperature time that second stage intensification constant temperature is fired is preferably 3～6h, more preferably 3.5～5.5h, most preferably 4～5h.
The present invention is incubated under sintering temperature (T1), and blank is carried out further presintering, blank under this insulation platform Diffusion densification stage is basically completed, and blank shrinks and is basically completed, but organizational structure is also not up to ideal state.
The bis sintering intermediate that above-mentioned steps is obtained by the present invention subsequently, after carrying out phase III cooling, obtains three sections Sintering intermediate.
The parameter that the described phase III is lowered the temperature by the present invention is not particularly limited, and those skilled in the art can be according to reality The condition of production, useful load, oxygen content and green compact size etc. select or adjust, the cooling of phase III of the present invention cooling Mode is preferably natural cooling, more preferably with stove natural cooling.Temperature after the cooling that the described phase III is lowered the temperature by the present invention Degree is not particularly limited, and those skilled in the art can enter according to practical condition, useful load, oxygen content and green compact size etc. Row selects or adjusts, and the temperature after the cooling of phase III of the present invention cooling is preferably 700～800 DEG C, and more preferably 720 ～780 DEG C, most preferably 740～760 DEG C.
The three-stage sintering intermediate that above-mentioned steps is finally obtained by the present invention, carries out after fourth stage intensification constant temperature fires, Obtain neodymium iron boron magnetic body blank.
The parameter that described fourth stage intensification constant temperature is fired by the present invention is not particularly limited, and those skilled in the art are permissible Select according to practical condition, useful load, oxygen content and green compact size etc. or adjust, described fourth stage intensification constant temperature The heating rate fired is preferably 5～7 DEG C/min, more preferably 5.5～6.5 DEG C/min, most preferably 5.7～6.3 DEG C/min. The thermostat temperature that described fourth stage intensification constant temperature is fired by the present invention is not particularly limited, and those skilled in the art can basis Practical condition, useful load, oxygen content and green compact size etc. select or adjust, and fourth stage of the present invention heats up permanent The thermostat temperature that temperature is fired is preferably sintering temperature～(sintering temperature+20 DEG C), i.e. 1000～1120 DEG C, more preferably 1020～ 1100 DEG C, more preferably 1040～1080 DEG C, most preferably 1050～1060 DEG C.The present invention is to described fourth stage intensification constant temperature The constant temperature time fired is not particularly limited, those skilled in the art can according to practical condition, useful load, oxygen content and Green compact size etc. selects or adjusts, and the constant temperature time that phase III intensification constant temperature of the present invention is fired is preferably 5～8h, More preferably 5.5～7.5h, most preferably 6～7h.
The present invention, after second stage intensification constant temperature is fired, is the most directly warmed up to T1 DEG C without insulation after being lowered the temperature by blank ～(T1+20) DEG C carries out fourth stage intensification constant temperature and fire, on the one hand it is to avoid long-time insulation at a sintering temperature to go out Existing abnormal grain! growth or average grain size are excessive, on the other hand again can promote blank at T1 DEG C～(T1+20) DEG C insulation Spreading densification further, make blank fully shrink, organizational structure reaches perfect condition, prevents sintering temperature or sintering time not The blank underburnt caused enough, thus after avoiding burning, blank squareness is on the low side.The above-mentioned whole step of the present invention is the most preferably in vacuum Carrying out under state, to ensure that blank is not oxidized, the mechanical pump of evacuation unit to be kept and lobe pump are in running status.
After described fourth stage intensification constant temperature is fired by the present invention, i.e. technique after sintering is not particularly limited, with ability Conventional steps known to field technique personnel, the present invention is preferably cooling step, or cooling step and tempering step；The present invention The concrete technology of described cooling step is not particularly limited, and those skilled in the art can be according to actual production process, shove charge Amount, the concrete size of product and properties of product carry out selective control, and the present invention is to improve firing of neodymium iron boron magnetic body pressed compact Effect and the magnetic property of neodymium iron boron magnetic body, the present invention preferably cools down under conditions of nitrogen or noble gas, more preferably Under conditions of nitrogen or noble gas air-cooled, more specifically the most air-cooled to less than 100 DEG C under conditions of argon；The present invention is to institute The speed stating cooling is not particularly limited, with correlation step in neodymium iron boron magnetic body sintering process well known to those skilled in the art Cooldown rate, those skilled in the art can be carried out according to the actual production process of sintering furnace, batch and product size Corresponding regulation, the speed of cooling of the present invention is 0.1～0.5 DEG C/min, more preferably 0.2～0.4 DEG C/min, most preferably It is 0.25～0.35 DEG C/min.
The concrete steps of described tempering step are not particularly limited by the present invention, with neodymium ferrum well known to those skilled in the art The concrete steps of boron magnet temper, those skilled in the art can be according to the actual production process of sintering furnace, shove charge Amount and product size regulate accordingly, and tempering step of the present invention preferably includes one-level tempering and second annealing；Described The temperature of one-level tempering is preferably 850～950 DEG C, more preferably 870～930 DEG C, most preferably 890～910 DEG C；Described one-level The time of tempering is preferably 4～6h, more preferably 4.5～5.5h, most preferably 4.7～5.3h.The temperature of described second annealing It is preferably 460～600 DEG C, more preferably 480～580 DEG C, most preferably 500～560 DEG C；The time of described second annealing is preferred It is 3～6h, more preferably 3.5～5.5h, most preferably 4～5h.
Although the present invention have employed the method for substep narration in above narration, but those skilled in the art can be correct Understanding, above-mentioned steps of the present invention is a whole set of continuous firing i.e. sintering process, has continuous print sintering curre.Company of the present invention It is neodymium iron boron magnetic body pressed compact sintering process temperature curve schematic diagram in the present invention that continuous sintering curre sees Fig. 1, Fig. 1.Such as Fig. 1 institute Showing, 1 fires intensification for defat, and 2 is defat platform constant temperature, and 3 fire intensification for degassing for the first time, and 4 fire flat for degassing for the first time Platform constant temperature, 5 fire intensification for second time degassing, and 6 fire platform constant temperature for second time degassing, and 7 is that first stage intensification constant temperature burns System heats up, and 8 fire constant temperature for first stage intensification constant temperature, and 9 fire intensification for second stage intensification constant temperature, and 10 is second stage liter Temperature constant temperature fires constant temperature, and 11 is phase III temperature-fall period, and 12 fire intensification for fourth stage intensification constant temperature, and 13 is fourth stage Intensification constant temperature fires constant temperature, and 14 is cooling.
The present invention has obtained neodymium iron boron magnetic body blank through above-mentioned steps, then processes through Post isothermal treatment and post processing After, obtain finished product neodymium iron boron magnetic body.Selection, concrete steps and the technique that above-mentioned Post isothermal treatment and post processing are processed by the present invention Etc. being not particularly limited, with the post-processing steps in neodymium iron boron magnetic body well known to those skilled in the art, this area skill Art personnel can be in optimized selection according to practical condition and prescription.
Above-mentioned steps of the present invention has obtained a kind of multi-steps sintering method of neodymium iron boron magnetic body, and the present invention is in neodymium-iron-boron system In standby numerous steps, start with from sintering process, use above-mentioned multi-steps sintering method, can significantly prevent neodymium iron boron magnetic body Crystal grain is grown up, it is thus achieved that crystal grain is tiny, the magnet that density is homogeneous, thus significantly improves the magnetic property of magnet, especially for nothing The neodymium iron boron powder body of one or more during heavy rare earth content, fine size and oxygen content are low, concrete superior technique effect, it is possible to Obtain crystal grain without exception to grow up, and there is the neodymium iron boron blank of more preferable remanent magnetism and squareness.Test result indicate that, the present invention carries The sintering method of the neodymium iron boron magnetic body of confession, when producing formula of the same race, even grain size, crystal grain without exception is grown up, and compares routine Method squareness can improve 2%～8%, and coercivity can improve 1%～5%.
In order to further illustrate the present invention, below in conjunction with the sintering of a kind of neodymium iron boron magnetic body that the present invention is provided by embodiment Method is described in detail, but it is to be understood that these embodiments are to implement under premised on technical solution of the present invention, Give detailed embodiment and concrete operating process, simply for further illustrating the features and advantages of the present invention, and not Being limiting to the claimed invention, protection scope of the present invention is also not necessarily limited to following embodiment.
Embodiment 1
The present embodiment uses and is designed to be divided into (PrNd)32.5B0.88Al0.66Cu0.15Co1.2Ga0.5Zr0.2FeRemainingFormula is equipped with Raw material, uses rejection tablet, and hydrogen is quick-fried, airflow milling technique, uses fully-automatic sealing press to suppress, isostatic pressed, then according to the present invention Sintering method be sintered, then carry out firsts and seconds tempering, the blank test performance obtained and tissue metallographic.
It is first according to 32.5% praseodymium neodymium, 0.88% boron, 0.66% aluminum, 0.15% bronze medal, 1.2% cobalt, 0.5% gallium, 0.2% Zirconium, the ratio of remaining ferrum is equipped with raw material.
Then use belt-rejecting technology, by raw material melting, get rid of band and be prepared as getting rid of strap, get rid of strap THICKNESS CONTROL at 0.25- Between 0.3mm.
Then use hydrogen quick-fried+airflow milling technique will get rid of strap and wear into fine powder, powder particle size controls between 2.6-2.8um.
Using and seal full automatic press, alignment magnetic field >=1.5T, green density controls 3.7～4.1g/cm3, pressure Make square blank, wait pressure pressure 230Mpa.
Being placed in sintering furnace by neodymium iron boron pressed compact, begin to warm up intensification to below 0.3Pa after evacuation, intensification 40min arrives It is incubated 150min after 250 DEG C, is then passed through 70min and is warmed up to 650 DEG C, be incubated 80min at 650 DEG C, be then passed through 40min and heat up To 850 DEG C, it is incubated 250min at 850 DEG C, then is warmed up to 1010 DEG C of insulation 30min through 60min, be then passed through 10min and heat up To 1030 DEG C, at 1030 DEG C, it is incubated 5h.Then cool to 700 DEG C through 90min, then be warmed up to 1030 DEG C through 90min, It is incubated 7h at 1030 DEG C and naturally cools to room temperature, the neodymium iron boron magnetic body blank after being sintered.
Blank after oversintering is warmed up to 900 DEG C of insulation 5h and carries out one-level tempering, and then cooling is warmed up to 520 DEG C of guarantors Temperature 3h carries out second annealing, obtains neodymium iron boron magnetic body.
See the sintering curre figure of the multi-steps sintering method that Fig. 1, Fig. 1 provide for the present invention.
The neodymium iron boron magnetic body preparing above-mentioned steps detects, and sees the neodymium that Fig. 2, Fig. 2 are the embodiment of the present invention 1 preparation The metallograph of iron boron magnet blank.
As seen from Figure 2, neodymium iron boron magnetic body crystallite dimension prepared by this sintering method is less, and crystallite dimension is the most equal Even, and crystal grain without exception is grown up.
The neodymium iron boron magnetic body preparing above-mentioned steps carries out magnetism testing, and result sees table 1, and table 1 is implemented for the present invention Neodymium iron boron magnetic body magnetic property prepared by example and the correction data of neodymium iron boron magnetic body magnetic property prepared by common process.
By the embodiment in table 1 and comparative example performance data it can be seen that this sintering method neodymium iron boron magnetic body of preparing Magnetic property significantly improves compared with the prior art, and especially in comparative example 2, coercivity and squareness are poor, illustrates to burn in comparative example 2 Credit balance is burnt.
Thus the sintering method of the present invention, can effectively avoid while inhibiting grain growth sintering underburnt.
Embodiment 2
The present embodiment uses and is designed to be divided into (PrNd)32.5B0.88Al0.66Cu0.15Co1.2Ga0.5Zr0.2FeRemainingFormula is equipped with Raw material, uses rejection tablet, and hydrogen is quick-fried, airflow milling technique, uses fully-automatic sealing press to suppress, isostatic pressed, then according to the present invention Sintering method be sintered, then carry out firsts and seconds tempering, the blank test performance obtained and tissue metallographic.
It is first according to 32.5% praseodymium neodymium, 0.88% boron, 0.66% aluminum, 0.15% bronze medal, 1.2% cobalt, 0.5% gallium, 0.2% Zirconium, the ratio of remaining ferrum is equipped with raw material.
Then use belt-rejecting technology, by raw material melting, get rid of band and be prepared as getting rid of strap, get rid of strap THICKNESS CONTROL at 0.25- Between 0.3mm.
Then use hydrogen quick-fried+airflow milling technique will get rid of strap and wear into fine powder, powder particle size controls between 2.6-2.8um.
Using and seal full automatic press, alignment magnetic field >=1.5T, green density controls 3.7～4.1g/cm3, pressure Make square blank, wait pressure pressure 230Mpa.
Being placed in sintering furnace by neodymium iron boron pressed compact, begin to warm up intensification to below 0.3Pa after evacuation, intensification 40min arrives It is incubated 150min after 250 DEG C, is then passed through 70min and is warmed up to 650 DEG C, be incubated 80min at 650 DEG C, be then passed through 40min and heat up To 850 DEG C, it is incubated 250min at 850 DEG C, then is warmed up to 1010 DEG C of insulation 30min through 60min, be then passed through 10min and heat up To 1022 DEG C, at 1022 DEG C, it is incubated 4h.Then cool to 700 DEG C through 90min, then be warmed up to 1032 DEG C through 90min, It is incubated 8h at 1032 DEG C and naturally cools to room temperature, the neodymium iron boron magnetic body blank after being sintered.
Blank after oversintering is warmed up to 900 DEG C of insulation 5h and carries out one-level tempering, and then cooling is warmed up to 520 DEG C of guarantors Temperature 3h carries out second annealing, obtains neodymium iron boron magnetic body.
The neodymium iron boron magnetic body preparing above-mentioned steps detects, and sees the neodymium that Fig. 3, Fig. 3 are the embodiment of the present invention 2 preparation The metallograph of iron boron magnet blank.
As seen from Figure 3, neodymium iron boron magnetic body crystallite dimension prepared by this sintering method is less, and crystallite dimension is the most equal Even, and crystal grain without exception is grown up.
The neodymium iron boron magnetic body preparing above-mentioned steps carries out magnetism testing, and result sees table 1, and table 1 is implemented for the present invention Neodymium iron boron magnetic body magnetic property prepared by example and the correction data of neodymium iron boron magnetic body magnetic property prepared by common process.
By the embodiment in table 1 and comparative example performance data it can be seen that this sintering method neodymium iron boron magnetic body of preparing Magnetic property significantly improves compared with the prior art, and especially in comparative example 2, remanent magnetism and squareness are poor, illustrates to sinter in comparative example 2 Underburnt.
Thus the sintering method of the present invention, can effectively avoid while inhibiting grain growth sintering underburnt.
Embodiment 3
The present embodiment uses and is designed to be divided into (PrNd)30.6Dy1.2B0.88Al0.5Cu0.15Co1.2Ga0.32Zr0.17FeRemainingFormula Being equipped with raw material, use rejection tablet, hydrogen is quick-fried, airflow milling technique, uses fully-automatic sealing press to suppress, isostatic pressed, then according to this The sintering method of invention is sintered, and then carries out firsts and seconds tempering, the blank test performance obtained and tissue metallographic.
It is first according to 30.6% praseodymium neodymium, 1.2% dysprosium, 0.88% boron, 0.5% aluminum, 0.15% bronze medal, 1.2% cobalt, 0.32% Gallium, 0.17% zirconium, the ratio of remaining ferrum is equipped with raw material.
Then use belt-rejecting technology, by raw material melting, get rid of band and be prepared as getting rid of strap, get rid of strap THICKNESS CONTROL at 0.25- Between 0.3mm.
Then use hydrogen quick-fried+airflow milling technique will get rid of strap and wear into fine powder, powder particle size controls between 2.6-2.8um.
Using and seal full automatic press, alignment magnetic field >=1.5T, green density controls at 3.7-4.1g/cm3, compacting Become square blank, wait pressure pressure 230Mpa.
Being placed in sintering furnace by neodymium iron boron pressed compact, begin to warm up intensification to below 0.3Pa after evacuation, intensification 40min arrives It is incubated 150min after 250 DEG C, is then passed through 70min and is warmed up to 650 DEG C, be incubated 80min at 650 DEG C, be then passed through 40min and heat up To 850 DEG C, it is incubated 250min at 850 DEG C, then is warmed up to 1010 DEG C of insulation 30min through 60min, be then passed through 10min and heat up To 1030 DEG C, at 1030 DEG C, it is incubated 5h.Then cool to 700 DEG C through 90min, then be warmed up to 1045 DEG C through 90min, It is incubated 5h at 1045 DEG C and naturally cools to room temperature, the neodymium iron boron magnetic body blank after being sintered.
Blank after oversintering is warmed up to 900 DEG C of insulation 5h and carries out one-level tempering, and then cooling is warmed up to 540 DEG C of guarantors Temperature 3h carries out second annealing, obtains neodymium iron boron magnetic body.
The neodymium iron boron magnetic body preparing above-mentioned steps detects, and sees the neodymium that Fig. 4, Fig. 4 are the embodiment of the present invention 3 preparation The metallograph of iron boron magnet blank.
As seen from Figure 4, neodymium iron boron magnetic body crystallite dimension prepared by this sintering method is less, and crystallite dimension is the most equal Even, and crystal grain without exception is grown up.
The neodymium iron boron magnetic body preparing above-mentioned steps carries out magnetism testing, and result sees table 1, and in table 1, magnet is square Degree is good, the state that remanent magnetism and coercivity are ideal in the case of all reaching same formula.
Thus the sintering method of the present invention, can effectively avoid while inhibiting grain growth sintering underburnt.
Comparative example 1
Neodymium iron boron pressed compact is placed in sintering furnace by the blank after embodiment 1 being suppressed, and starts to below 0.3Pa after evacuation Heat temperature raising, is incubated 150min, is then passed through 70min and is warmed up to 650 DEG C, 650 DEG C of insulations after intensification 40min to 250 DEG C 80min, is then passed through 40min and is warmed up to 850 DEG C, is incubated 250min at 850 DEG C, then entered 60min and be warmed up to 1010 DEG C of insulations 30min, is then passed through 10min and is warmed up to 1030 DEG C, naturally cools to room temperature after being incubated 12h at 1030 DEG C.
Blank after oversintering is warmed up to 900 DEG C of insulation 5h and carries out one-level tempering, and then cooling is warmed up to 520 DEG C of guarantors Temperature 3h carries out second annealing.
The neodymium iron boron magnetic body preparing above-mentioned common process carries out magnetism testing, and result sees table 1, and table 1 is the present invention Neodymium iron boron magnetic body magnetic property prepared by embodiment and the correction data of neodymium iron boron magnetic body magnetic property prepared by common process.
Comparative example 2
Neodymium iron boron pressed compact is placed in sintering furnace by the blank after embodiment 1 being suppressed, and starts to below 0.3Pa after evacuation Heat temperature raising, is incubated 150min, is then passed through 70min and is warmed up to 650 DEG C, 650 DEG C of insulations after intensification 40min to 250 DEG C 80min, is then passed through 40min and is warmed up to 850 DEG C, is incubated 250min at 850 DEG C, then is warmed up to 1010 DEG C of insulations through 60min 30min, is then passed through 10min and is warmed up to 1030 DEG C, naturally cools to room temperature, obtain neodymium-iron-boron at 1030 DEG C after being incubated 8h Chaeta base.
Blank after oversintering is warmed up to 900 DEG C of insulation 5h and carries out one-level tempering, and then cooling is warmed up to 520 DEG C of guarantors Temperature 3h carries out second annealing, obtains neodymium iron boron magnetic body.
The neodymium iron boron magnetic body preparing above-mentioned steps detects, and sees the neodymium that Fig. 5, Fig. 5 are comparative example 2 of the present invention preparation The metallograph of iron boron magnet blank.
As seen from Figure 5, the neodymium iron boron magnetic body crystallite dimension of conventional preparation is thick uneven, and exists the most different Often crystal grain is grown up.
The neodymium iron boron magnetic body preparing above-mentioned common process carries out magnetism testing, and result sees table 1, and table 1 is the present invention Neodymium iron boron magnetic body magnetic property prepared by embodiment and the correction data of neodymium iron boron magnetic body magnetic property prepared by common process.
Neodymium iron boron magnetic body magnetic property prepared by table 1 embodiment of the present invention and neodymium iron boron magnetic body magnetic prepared by common process The correction data of energy.
Above the sintering method of a kind of neodymium iron boron magnetic body that the present invention provides is described in detail, used herein Principle and the embodiment of the present invention are set forth by specific case, and the explanation of above example is only intended to help to understand The method of the present invention and core concept thereof, including best mode, and also make any person skilled in the art can be real Trample the present invention, including manufacturing and using any device or system, and the method implementing any combination.It should be pointed out that, for this skill For the those of ordinary skill in art field, under the premise without departing from the principles of the invention, it is also possible to the present invention is carried out some changing Entering and modify, these improve and modify in the protection domain also falling into the claims in the present invention.The scope of patent protection of the present invention Be defined by the claims, and those skilled in the art can be included it is conceivable that other embodiments.If these other real Execute example and there is the structural element being not different from claim character express, if or they include the word with claim State the equivalent structural elements without essence difference, then these other embodiments also should comprise within the scope of the claims.

Claims (10)

1. the sintering method of a neodymium iron boron magnetic body, it is characterised in that comprise the following steps:
A) under conditions of vacuum or protective gas, by neodymium iron boron magnetic body pressed compact after through the primary stage, ladder-elevating temperature is fired, Obtain just section sintering intermediate；
B) first section sintering intermediate above-mentioned steps obtained, carries out after first stage intensification constant temperature fires, obtaining one-stage sintering Intermediate；
C) one-stage sintering intermediate above-mentioned steps obtained, carries out after second stage intensification constant temperature fires, obtaining bis sintering Intermediate；
D) bis sintering intermediate above-mentioned steps obtained, after carrying out phase III cooling, obtains three-stage sintering intermediate；
E) three-stage sintering intermediate above-mentioned steps obtained, carries out after fourth stage intensification constant temperature fires, obtaining neodymium-iron-boron Chaeta base.
Sintering method the most according to claim 1, it is characterised in that described primary stage ladder-elevating temperature is fired and included successively Defat is fired, degassing for the first time is fired and second time degassing is fired.
Sintering method the most according to claim 2, it is characterised in that the heating rate that described defat is fired is 5～6 DEG C/ min；The thermostat temperature that described defat is fired is 200～300 DEG C；The constant temperature time that described defat is fired is 1～2h；
The heating rate that the degassing of described first time is fired is 5～6 DEG C/min；The thermostat temperature that the degassing of described first time is fired is 500～700 DEG C；The constant temperature time that the degassing of described first time is fired is 2～3h；
The heating rate that the degassing of described second time is fired is 4～5 DEG C/min；The temperature fired of described second time degassing be 800～ 900℃；The constant temperature time that the degassing of described second time is fired is 3～5h.
4. according to the sintering method described in Claims 1 to 4 any one, it is characterised in that described first stage intensification constant temperature The heating rate fired is 2～3 DEG C/min；
The thermostat temperature that described first stage intensification constant temperature is fired is (sintering temperature-20 DEG C)；
The constant temperature time that described first stage intensification constant temperature is fired is 0～1h；
The sintering temperature of described neodymium iron boron magnetic body is 1000～1100 DEG C.
Sintering method the most according to claim 4, it is characterised in that the intensification speed that described second stage intensification constant temperature is fired Rate is 2～3 DEG C/min；
The thermostat temperature that described second stage intensification constant temperature is fired is sintering temperature；
The constant temperature time that described second stage intensification constant temperature is fired is 3～6h.
Sintering method the most according to claim 5, it is characterised in that the mode of cooling of described phase III is that nature is cold But；
Temperature after the cooling of described phase III is 700～800 DEG C.
Sintering method the most according to claim 6, it is characterised in that the intensification speed that described fourth stage intensification constant temperature is fired Rate is 5～7 DEG C/min；
The thermostat temperature that described fourth stage intensification constant temperature is fired is sintering temperature～(sintering temperature+20 DEG C)；
The constant temperature time that described fourth stage intensification constant temperature is fired is 5～8h.
Sintering method the most according to claim 1, it is characterised in that described fourth stage intensification constant temperature also includes after firing Cooling step；
Described cooling step is specially air-cooled under conditions of nitrogen or noble gas, and the speed of described cooling is 0.1～0.5 ℃/min。
Sintering method the most according to claim 8, it is characterised in that also include tempering step after described cooling step；
Described tempering step includes one-level tempering and second annealing；
The temperature of described one-level tempering is 850～950 DEG C；The time of described one-level tempering is 4～6h；
The temperature of described second annealing is 460～600 DEG C；The time of described second annealing is 3～6h.
10. a neodymium iron boron magnetic body, it is characterised in that obtained after multi-steps sintering by neodymium iron boron magnetic body pressed compact；
The hop count of described segmentation is four sections or five sections；
Described neodymium iron boron magnetic body raw material, composition includes by mass percentage: Pr-Nd:28%～33%；Dy:0～10%；Tb:0 ～10%；Nb:0～5%；Al:0～1%；B:0.5%～2.0%；Cu:0～1%；Co:0～3%；Ga:0～2%；Gd:0 ～2%；Ho:0～2%；Zr:0～2%；Surplus is Fe.
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CN106782974A (en) * 2016-12-26 2017-05-31 浙江中科磁业有限公司 A kind of preparation method of neodymium iron boron magnetic body
CN106623916A (en) * 2016-12-28 2017-05-10 京磁新材料有限公司 Low-temperature sintering method for preparing neodymium-iron-boron magnet
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CN106601406B (en) * 2017-01-03 2019-04-30 京磁材料科技股份有限公司 Prepare the sintering method of neodymium iron boron magnetic body
CN106920616A (en) * 2017-03-17 2017-07-04 京磁材料科技股份有限公司 A kind of sintering method of neodymium iron boron magnetic body
CN106992052A (en) * 2017-03-17 2017-07-28 京磁材料科技股份有限公司 Utilize the method for sintered NdFeB waste-material-preparing high-performance Ne-Fe-B
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CN109216007A (en) * 2018-09-07 2019-01-15 杭州永磁集团有限公司 A kind of preparation process of samarium-cobalt magnet
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US11569012B2 (en) 2019-11-06 2023-01-31 Yantai Dongxing Magnetic Materials Inc. Method for improving performance of sintered NdFeB magnets
CN113948303A (en) * 2021-10-20 2022-01-18 合肥工业大学 High-yield and high-performance sintered NdFeB radiation ring and preparation method thereof

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