CN105741995A - High-performance sintered neodymium-iron-boron permanent magnet and preparation method thereof - Google Patents

Abstract

The invention discloses a high-performance sintered neodymium-iron-boron permanent magnet, which is prepared from the following raw materials: 30wt%-32.5wt% of PrNd, 0.92wt%-1wt% of B, 0.05wt%-0.8wt% of Al, 0.05wt%-0.3wt% of Cu, 0.5wt%-2wt% of Co, 0.1wt%-0.5wt% of Zr, 0.05wt%-0.5wt% of Ga and the balance of Fe. The cast sheet microstructure is optimized and the process parameters of the volume average particle size SMD and particle size distribution X90/X10 of powder and the like are controlled by optimizing composition elements and controlling the smelting casting temperature, so that the 52M and 48H high-performance neodymium-iron-boron magnet is prepared; the production technology is simple; the production period is short; the oxygen content control requirements in the process are consistent with the ordinary medium-low performance requirements and are consistent with those of a conventional magnet production process; and the production process does not need to be specially treated.

Description

A kind of high performance sintered neodymium-iron-boron permanent magnet and preparation method thereof

Technical field

The invention belongs to rare-earth permanent-magnet material technical field, be specifically related to a kind of low cost (without dysprosium) 52M and 48H and sinter neodymium Ferrum boron permanent magnet and preparation method thereof.

Background technology

Sintered NdFeB magnet, as third generation permanent magnet material, has the feature of high energy product and high-coercive force.High Energy Product magnet Device miniaturization, lightweight can be made, thus be used widely in the field such as computer, communication.Small-sized along with magnet Changing, machining and the plating of magnet are relatively big to the damage of magnet, thus cause magnet cannot meet heatproof requirement.At present, The heatproof requirement of magnet is mainly met by improving the HCJ of magnet.For 52M and the 48H trade mark, at present Mainly by adding a certain amount of dysprosium or terbium or using dual alloy technique to reach performance requirement.

Owing to dysprosium and terbium are expensive, add part dysprosium or terbium, add the cost of magnet, reduce the market competitiveness.With Time owing to adding dysprosium or terbium, reduce the Br of magnet, in order to make Br can reach trade mark standard-required, can only be dilute by reducing Soil total amount reaches Br requirement, in such event, process of factory production management and control be also been proposed higher requirement, and for mesh Before commonly used control oxygen technique factory for, be extremely difficult to low oxygen process requirement (magnet Control for Oxygen Content exists Below 800ppm).Although other dual alloy technique is without adding dysprosium or terbium, but due to dual alloy (main-phase alloy, Auxiliary phase metal) need to prepare respectively, i.e. main-phase alloy includes the processing steps such as broken, the powder process of melting, hydrogen, and auxiliary phase alloy also wraps Include after processing step, main-phase alloy and the auxiliary phase alloy powder process such as broken, the powder process of hydrogen complete and also need blending processes of powders step, technological process Numerous and diverse, for general Nd-Fe-B permanent magnet processing and manufacturing manufacturer, need large number quipments to put into and transformation, cost is high.

Summary of the invention

Present invention aims to the deficiencies in the prior art, it is provided that a kind of high performance sintered neodymium-iron-boron permanent magnet and preparation thereof Method, average to optimize slab microstructure and control powder volume by optimizing component and control melting cast temperature The technological parameters such as particle diameter SMD and particle size distribution X90/X10, to prepare 52M and 48H high-performance neodymium-iron-boron magnet, produce work Skill is simple, with short production cycle, process Control for Oxygen Content requires to require consistent with common middle low performance, and raw with conventional magnet Production. art is consistent, and production process is without special treatment.

To achieve these goals, the technical solution adopted in the present invention is:

A kind of high performance sintered neodymium-iron-boron permanent magnet, described permanent magnet is made up of the raw material including following components, PrNd: 30-32.5wt%, B:0.92-1wt%, Al:0.05-0.8wt%, Cu:0.05-0.3wt%, Co:0.5-2wt%, Zr:0.1-0.5wt%, Ga:0.05-0.5wt%, Fe surplus.

Wherein, in described component PrNd, Pr content 25%, purity is more than 99.5%；Described component Fe is that carbon content is less than The high purity iron of 100ppm.Sintered permanent magnet oxygen content is less than 1000ppm.

Preferably scheme, a kind of 52M sintered Nd-Fe-B permanent magnet, described permanent magnet is made up of the raw material including following components, PrNd:30.4wt%, B:0.96wt%, Al:0.1wt%, Cu:0.2wt%, Co:0.5wt%, Zr:0.15wt%, Ga:0.1wt%, Fe surplus.

Preferably scheme, a kind of 48H sintered Nd-Fe-B permanent magnet, described permanent magnet is made up of the raw material including following components, PrNd:32.0wt%, B:0.94wt%, Al:0.5wt%, Cu:0.2wt%, Co:1.0wt%, Zr:0.15wt%, Ga:0.1wt%, Fe surplus.

The preparation method of a kind of high performance sintered neodymium-iron-boron permanent magnet, comprises the following steps:

1) optimal cast temperature is calculated:

$T=\underset{i=1}{\overset{n}{\Σ}}(E_i*W_i)+k;$

Wherein, T is optimal cast temperature, E_iFor the fusing point of each alloying element, W_iFor the mass fraction of each alloying element, k is Temperature coefficient, 90 DEG C < k < 110 DEG C, usually, k=100 DEG C；The fusing point temperature of the most each alloying element (crystal or noncrystal) It is optimal cast temperature that the summation of degree and this alloying element mass fraction accounting product adds temperature coefficient；

2) dispensing: the raw material of each alloying element is weighed by the mass fraction accounting of its correspondence；

3) melting: by step 2) in raw material be sequentially loaded in rapid hardening furnace crucible by the disentegrated particles such as iron staff, ferro-boron, praseodymium neodymium, Rapid hardening furnace being evacuated to below 5Pa, starts baking material, baking material reaches 10-30 minute, when vacuum is less than 3Pa, and argon filling Gas, to-0.065Mpa, starts melting, continues melting 8-10 minute, molten steel is carried out refine melting after iron staff fusing, Refine smelting time is 2-5 minute, treats that alloy liquid level transfers silvery white to, starts thermometric, when temperature reaches step 1) in During good cast temperature T, start casting, obtain slab；

4) hydrogen is broken: by step 3) slab for preparing puts into and inhales hydrogen in hydrogen crushing furnace to the most saturated, be then heated to 500-600 DEG C and take off Hydrogen, to below 20Pa, obtains coarse powder；

5) powder process: in step 4) prepare coarse powder in add 0.05-0.2% antioxidant, wear in airflow milling volume put down All particle diameter SMD are 2.5-3.0 micron, and particle size distribution ratio X 90/X10 is the fine powder of less than 5.0, add in fine powder 0.05-0.2% lubricant；Wherein test instrunment is new handkerchief Tyke laser particle analyzer；

6) molding: step 5) fine powder for preparing obtains compact density at magnetic field of press more than the die for molding of 1.5T and is The green compact of 3.6-4.2g/cm3, seal box oxygen content is under nitrogen protection less than 0.05%；

7) isostatic pressed: by step 6) prepare green compact plastic sheeting wrap and put into after Vacuum Package in isostatic pressed press, Under 150-300MPa oil pressure, green density improves further to 4.4-4.8g/cm3；

8) sintering: under nitrogen protection, by step 7) prepare blank peel off vacuum bag and thin film, put into graphite, soon Speed enters stove, is evacuated to 5.0*10^-1Start to warm up after below Pa, be warming up to insulation 3-6 hour when 800-900 DEG C, make true Reciprocal of duty cycle is down to 10^-1Below Pa, is continuously heating to 1000-1100 DEG C and is sintered 2-10 hour；Terminate rear argon filling air cooling But to less than 100 DEG C, being warming up to 860-950 DEG C of insulation and within 1-4 hour, carry out one-level tempering, insulation terminates the cooling of rear applying argon gas To less than 80 DEG C, being warming up to 440-520 DEG C of insulation and within 3-6 hour, carry out second annealing, insulation terminates rear applying argon gas and is cooled to 60 DEG C Hereinafter come out of the stove；Prepare finished product.

Use after technique scheme, the present invention the most advantageously:

High performance sintered neodymium-iron-boron permanent magnet of the present invention, owing to accurately controlling melting cast temperature, thus can obtain Good slab microstructure, specifically, in Sintered NdFeB magnet production process, the melting topmost task of casting is Control slab (ingot casting) microstructure, the microstructure of slab (ingot casting) not only to powder process, orientation, sintering process, And the magnetic property of powder properties and final sintered magnet is all had a major impact, excellent slab (ingot casting) microstructure, Requiring to there is not α-Fe, there is not tiny equiax crystal region, have the flake crystalline penetrated, 2:14:1 phase flake crystalline thickness is 3 μm ± 0.5 μm, the rich neodymium flake crystalline crystal boundary that hands down is uniformly distributed, the most domestic vacuum induction slab stove commonly used, phase For to, structure and the control slab thickness of equipment have basically reached the control to slab rate of cooling, excellent for obtaining Good slab microstructure provides guarantee, but owing to universal cast temperature is 1450-1500 DEG C of scope, this scope be through Test scope, do not consider the difference of different formulations fusing point, and according to practical experience, cast temperature is higher than alloy melting point 100 DEG C During left and right, available optimal slab microstructure, cast temperature is too low is likely to be due to part refractory material (ferro-niobium and ferrozirconium) Do not change so that actual constituent changes, thus affected microstructure, follow-up sintering technique even magnetic property, material output Rate is also greatly affected；Cast temperature is higher or too high, may cause the generation of more equiax crystal even α-Fe, thus difficult To obtain optimal slab microstructure, therefore, by calculating alloy theory fusing point, thus melting cast temperature is controlled, with Obtain optimal slab microstructure, lay a solid foundation for manufacturing high-performance neodymium-iron-boron magnet.It addition, again by controlling powder Volume average particle size (SMD) and particle size distribution (X90/X10), be aided with suitable sintering process, obtain crystal grain average particle Spend the blank at 5-7 micron, it is achieved improved the purpose of magnet performance by crystal grain thinning.Of the present invention high performance sintered Without the heavy rare earth element such as dysprosium, terbium in Nd-Fe-B permanent magnet, magnet formulation cost is low, and production technology is simple, produce week Phase is short, the requirement of process Control for Oxygen Content is consistent and consistent with conventional magnet production technology with common middle low performance requirement, raw Product process is without special treatment.

Detailed description of the invention

The following stated is only presently preferred embodiments of the present invention, the most therefore limits protection scope of the present invention.

Embodiment 1

A kind of 52M sintered Nd-Fe-B permanent magnet, described permanent magnet is made up of the raw material including following components, PrNd:30.4wt%, B:0.96wt%, Al:0.1wt%, Cu:0.2wt%, Co:0.5wt%, Zr:0.15wt%, Ga:0.1wt%, Fe surplus.Wherein, in described component PrNd, Pr content 25%, purity is more than 99.5%；Described component Fe is carbon content High purity iron less than 100ppm.Sintered permanent magnet oxygen content is less than 1000ppm.

The preparation method of the 52M sintered Nd-Fe-B permanent magnet described in the present embodiment, comprises the following steps:

1) optimal cast temperature is calculated:

$T=\underset{i=1}{\overset{n}{\&Sigma;}}(E_i*W_i)+k;$

Wherein, T is optimal cast temperature, E_iFor the fusing point of each alloying element, W_iFor the mass fraction of each alloying element, k is Temperature coefficient, 90 DEG C < k < 110 DEG C, in the present embodiment, k=100 DEG C；Melting of the most each alloying element (crystal or noncrystal) It is optimal cast temperature that the summation of some temperature and this alloying element mass fraction accounting product adds temperature coefficient.

0.304*0.25+1010 DEG C of * of T=935 DEG C of * 0.0096+660.37 DEG C of * of 0.304*0.75+2300 DEG C of * 0.001+1083 DEG C *0.002+1495℃*0.005+1852℃*0.0015+29.78℃*0.001+1535℃*0.6759+100℃ =1474.04 DEG C.The most optimal cast temperature is 1474.04 DEG C.

Owing to accurately controlling melting cast temperature, thus optimal slab microstructure, i.e. slab can be obtained and there is not α-Fe, There is not tiny equiax crystal region, have the flake crystalline penetrated, 2:14:1 phase flake crystalline thickness is 3 μm ± 0.5 μm, rich The neodymium flake crystalline crystal boundary that hands down is uniformly distributed, and lays a solid foundation for manufacturing high-performance neodymium-iron-boron magnet.

2) dispensing: the raw material of each alloying element is weighed by the mass fraction accounting of its correspondence；PrNd:30.4wt%, B: 0.96wt%, Al:0.1wt%, Cu:0.2wt%, Co:0.5wt%, Zr:0.15wt%, Ga:0.1wt%, Fe Surplus；In component PrNd, Pr content 25%.

3) melting: by step 2) in raw material be sequentially loaded in rapid hardening furnace crucible by the disentegrated particles such as iron staff, ferro-boron, praseodymium neodymium, Rapid hardening furnace being evacuated to below 5Pa, starts baking material, baking material power is set to 80KW-120KW, and baking material reaches 20 minutes, when When vacuum is less than 3Pa, applying argon gas to-0.065Mpa, then power is increased to 500KW, starts melting, iron staff melts After continue melting 10 minutes, adjustment monitor system is 360KW, and molten steel carries out refine melting, and refine smelting time is 4 minutes, treat that alloy liquid level transfers silvery white to, start thermometric, when temperature reaches step 1) in optimal cast temperature 1474 ± 5 DEG C Time, start casting, obtain slab.

4) hydrogen is broken: by step 3) slab for preparing puts into and inhales hydrogen in hydrogen crushing furnace to the most saturated, is then heated to 550 DEG C of dehydrogenations extremely Below 20Pa, obtains coarse powder.

5) powder process: in step 4) prepare coarse powder in add 0.1% antioxidant, airflow milling is worn into volume average particle size SMD is 2.5 microns, and particle size distribution ratio X 90/X10 is the fine powder of less than 5.0, adds 0.1% lubricant in fine powder； Wherein test instrunment is new handkerchief Tyke laser particle analyzer.

6) molding: step 5) to obtain compact density at magnetic field of press more than the die for molding of 1.5T be 4g/cm3 for the fine powder for preparing Green compact, seal box oxygen content is under nitrogen protection less than 0.05%；

7) isostatic pressed: by step 6) prepare green compact plastic sheeting wrap and put into after Vacuum Package in isostatic pressed press, Under 200MPa oil pressure, green density improves further to 4.5g/cm3；

8) sintering: under nitrogen protection, by step 7) prepare blank peel off vacuum bag and thin film, put into graphite, soon Speed enters stove, is evacuated to 5.0*10^-1Start to warm up after below Pa, be warming up to insulation 4 hours when 800-900 DEG C, make vacuum Degree is down to 10^-1Below Pa, is continuously heating to 1075 DEG C and is sintered 4 hours；Terminate rear applying argon gas and be cooled to 100 DEG C Hereinafter, being warming up to 890 DEG C of insulations and within 2 hours, carry out one-level tempering, insulation terminates rear applying argon gas and is cooled to less than 80 DEG C, heats up Within 4 hours, carrying out second annealing to 500 DEG C of insulations, insulation terminates rear applying argon gas and is cooled to less than 60 DEG C and comes out of the stove；Prepare finished product.

Comparative example 1

A kind of 52M sintered Nd-Fe-B permanent magnet, described permanent magnet is made up of the raw material including following components, PrNd:29.2wt%, Tb:0.5wt%, B:1.0wt%, Al:0.1wt%, Cu:0.2wt%, Co:0.5wt%, Nb:0.4wt%, Ga: 0.1wt%, Fe surplus.

The preparation method of the 52M sintered Nd-Fe-B permanent magnet described in this comparative example, comprises the following steps:

1) dispensing: raw material is weighed to scale, PrNd:29.2wt%, Tb:0.5wt%, B:1.0wt%, Al: 0.1wt%, Cu:0.2wt%, Co:0.5wt%, Nb:0.4wt%, Ga:0.1wt%, Fe surplus.

2) melting: raw material is sequentially loaded in rapid hardening furnace crucible by the disentegrated particles such as iron staff, ferro-boron, praseodymium neodymium；Rapid hardening furnace is taken out Vacuum, to below 5Pa, starts baking material, and baking material power is set to 80KW-120KW；Baking material reaches about 20 minutes, works as vacuum During less than 3Pa, applying argon gas to-0.065Mpa, then power is increased to 500KW, starts melting；After iron staff fusing Continue melting 10 minutes, treat that alloy liquid level once transfers silvery white to, start casting, obtain slab；Hydrogen is broken: slab is put into Hydrogen crushing furnace inhales hydrogen to the most saturated, be then heated to 550 DEG C of dehydrogenations to below 20Pa, obtain coarse powder；

3) powder process: add 0.1% antioxidant in coarse powder, wearing into volume average particle size SMD in airflow milling is 3.3 microns, Particle size distribution ratio (X90/X10) is 5.5, and X50 is the fine powder of 5.0 microns, test instrunment is new handkerchief Tyke laser grain Degree tester.0.1% lubricant is added in fine powder；

4) molding: nitrogen protection is lower ensures that seal box oxygen content is less than 0.05%, and powder is more than the mould of 1.5T at magnetic field of press In tool, molding obtains the green compact that compact density is 4.0g/cm3；

5) isostatic pressed: plastic sheeting is wrapped and the blank of Vacuum Package is put in isostatic pressed press, under 200MPa oil pressure, Green density improves further to 4.5g/cm3；

6) sinter and be tempered: under nitrogen protection, peelling off vacuum bag and thin film, put into graphite, quickly entering stove, taking out true Empty to 5.0*10^-1Start to warm up after below Pa, be warming up to insulation 4 hours when 800-900 DEG C, make vacuum be down to 10^-1Pa Hereinafter, it is continuously heating to 1050 DEG C and is sintered 6 hours；Terminate rear applying argon gas and be cooled to less than 100 DEG C, be warming up to 890 DEG C of insulations carry out one-level tempering for 2 hours, and insulation terminates rear applying argon gas and is cooled to less than 80 DEG C, are warming up to 500 DEG C of insulations 4 Hour carrying out second annealing, insulation terminates rear applying argon gas and is cooled to less than 60 DEG C and comes out of the stove.

52M Sintered NdFeB magnet prepared by method described in embodiment 1 and the 52M sintered NdFeB prepared by comparative example 1 Magnet magnetic property measuring instrument measures, and its performance comparison is as follows:

Classification	Br(KGs)	Hcj(KOe)	(BH)max(MGOe)	Hk/Hcj
					Embodiment 1	14.45	14.51	51.46	0.98
Comparative example 1	14.36	14.32	49.71	0.97

As can be seen from the table above, its magnetic property of 52M magnet prepared by the present embodiment 1 method is prepared than comparative example 1 52M magnet performance is higher, and does not has heavy rare earth metal Dy or Tb in embodiment 1 formula, reduces formulation cost, with Time embodiment 1 total amount of rare earth higher, to production process control requirement lower.

Embodiment 2

A kind of 48H sintered Nd-Fe-B permanent magnet, described permanent magnet is made up of the raw material including following components, PrNd:32.0wt%, B:0.94wt%, Al:0.5wt%, Cu:0.2wt%, Co:1.0wt%, Zr:0.15wt%, Ga:0.1wt%, Fe surplus.Wherein, in described component PrNd, Pr content 25%, purity is more than 99.5%；Described component Fe is carbon content High purity iron less than 100ppm.Sintered permanent magnet oxygen content is less than 1000ppm.

The preparation method of the 52M sintered Nd-Fe-B permanent magnet described in the present embodiment, comprises the following steps:

1) optimal cast temperature is calculated:

$T=\underset{i=1}{\overset{n}{\&Sigma;}}(E_i*W_i)+k;$

Wherein, T is optimal cast temperature, E_iFor the fusing point of each alloying element, W_iFor the mass fraction of each alloying element, k is Temperature coefficient, 90 DEG C < k < 110 DEG C, in the present embodiment, k=100 DEG C；Melting of the most each alloying element (crystal or noncrystal) It is optimal cast temperature that the summation of some temperature and this alloying element mass fraction accounting product adds temperature coefficient.

0.32*0.25+1010 DEG C of * of T=935 DEG C of * 0.0094+660.37 DEG C of * of 0.32*0.75+2300 DEG C of * 0.005+1083 DEG C * 0.01+1852 DEG C of * of 0.002+1495 DEG C of * 0.001+1535 DEG C of * of 0.0015+29.78 DEG C of * 0.6711+100 DEG C=1461.48 DEG C. The most optimal cast temperature is 1461.48 DEG C.

Owing to accurately controlling melting cast temperature, thus optimal slab microstructure, i.e. slab can be obtained and there is not α-Fe, There is not tiny equiax crystal region, have the flake crystalline penetrated, 2:14:1 phase flake crystalline thickness is 3 μm ± 0.5 μm, rich The neodymium flake crystalline crystal boundary that hands down is uniformly distributed, and lays a solid foundation for manufacturing high-performance neodymium-iron-boron magnet.

2) dispensing: the raw material of each alloying element is weighed by the mass fraction accounting of its correspondence；PrNd:32.0wt%, B: 0.94wt%, Al:0.5wt%, Cu:0.2wt%, Co:1.0wt%, Zr:0.15wt%, Ga:0.1wt%, Fe Surplus；In component PrNd, Pr content 25%.

3) melting: by step 2) in raw material be sequentially loaded in rapid hardening furnace crucible by the disentegrated particles such as iron staff, ferro-boron, praseodymium neodymium, Rapid hardening furnace being evacuated to below 5Pa, starts baking material, baking material power is set to 80KW-120KW, and baking material reaches 20 minutes, when When vacuum is less than 3Pa, applying argon gas to-0.065Mpa, then power is increased to 500KW, starts melting, iron staff melts After continue melting 8 minutes, adjustment monitor system is 360KW, and molten steel carries out refine melting, and refine smelting time is 3 minutes, treat that alloy liquid level transfers silvery white to, start thermometric, when temperature reaches step 1) in optimal cast temperature 1461 ± 5 DEG C Time, start casting, obtain slab.

4) hydrogen is broken: by step 3) slab for preparing puts into and inhales hydrogen in hydrogen crushing furnace to the most saturated, is then heated to 550 DEG C of dehydrogenations extremely Below 20Pa, obtains coarse powder.

5) powder process: in step 4) prepare coarse powder in add 0.1% antioxidant, airflow milling is worn into volume average particle size SMD is 2.8 microns, and particle size distribution ratio X 90/X10 is the fine powder of 4.8, and X50 is the fine powder of 4.0 microns, at fine powder Middle addition 0.1% lubricant；Wherein test instrunment is new handkerchief Tyke laser particle analyzer.

6) molding: step 5) to obtain compact density at magnetic field of press more than the die for molding of 1.5T be 4g/cm3 for the fine powder for preparing Green compact, seal box oxygen content is under nitrogen protection less than 0.05%；

7) isostatic pressed: by step 6) prepare green compact plastic sheeting wrap and put into after Vacuum Package in isostatic pressed press, Under 200MPa oil pressure, green density improves further to 4.5g/cm3；

8) sintering: under nitrogen protection, by step 7) prepare blank peel off vacuum bag and thin film, put into graphite, soon Speed enters stove, is evacuated to 5.0*10^-1Start to warm up after below Pa, be warming up to insulation 4 hours when 800-900 DEG C, make vacuum Degree is down to 10^-1Below Pa, is continuously heating to 1075 DEG C and is sintered 4 hours；Terminate rear applying argon gas and be cooled to 100 DEG C Hereinafter, being warming up to 890 DEG C of insulations and within 2 hours, carry out one-level tempering, insulation terminates rear applying argon gas and is cooled to less than 80 DEG C, heats up Within 4 hours, carrying out second annealing to 500 DEG C of insulations, insulation terminates rear applying argon gas and is cooled to less than 60 DEG C and comes out of the stove；Prepare finished product.

Comparative example 2

A kind of 48H sintered Nd-Fe-B permanent magnet, described permanent magnet is made up of the raw material including following components, PrNd:29.2wt%, Tb:0.5wt%, B:1.0wt%, Al:0.1wt%, Cu:0.2wt%, Co:0.5wt%, Nb:0.4wt%, Ga: 0.1wt%, Fe surplus.

The preparation method of the 52M sintered Nd-Fe-B permanent magnet described in this comparative example, comprises the following steps:

1) dispensing: raw material is weighed to scale, PrNd:28.5wt%, Dy:2.0wt%, B:1.0wt%, Al: 0.1wt%, Cu:0.2wt%, Co:1.0wt%, Nb:0.4wt%, Ga:0.1wt%, Fe surplus.

2) melting: raw material is sequentially loaded in rapid hardening furnace crucible by the disentegrated particles such as iron staff, ferro-boron, praseodymium neodymium；Rapid hardening furnace is taken out Vacuum, to below 5Pa, starts baking material, and baking material power is set to 80KW-120KW；Baking material reaches about 20 minutes, works as vacuum During less than 3Pa, applying argon gas to-0.065Mpa, then power is increased to 500KW, starts melting；After iron staff fusing Continue melting 8 minutes, treat that alloy liquid level once transfers silvery white to, start casting, obtain slab；Hydrogen is broken: slab puts into hydrogen Broken stove inhales hydrogen to the most saturated, be then heated to 550 DEG C of dehydrogenations to below 20Pa, obtain coarse powder.

3) powder process: add 0.1% antioxidant in coarse powder, wearing into volume average particle size SMD in airflow milling is 3.3 microns, Particle size distribution ratio (X90/X10) is 5.5, and X50 is the fine powder of 5.0 microns, and test instrunment is new handkerchief Tyke laser particle size Tester.0.1% lubricant is added in fine powder.

4) molding: nitrogen protection is lower ensures that seal box oxygen content is less than 0.05%, and powder is more than the mould of 1.5T at magnetic field of press In tool, molding obtains the green compact that compact density is 4.0g/cm3；

5) isostatic pressed: plastic sheeting is wrapped and the blank of Vacuum Package is put in isostatic pressed press, under 200MPa oil pressure, Green density improves further to 4.5g/cm3；

6) sinter and be tempered: under nitrogen protection, peelling off vacuum bag and thin film, put into graphite, quickly entering stove, taking out true Empty to 5.0*10^-1Start to warm up after below Pa, be warming up to insulation 4 hours when 800-900 DEG C, make vacuum be down to 10^-1Pa Hereinafter, it is continuously heating to 1050 DEG C and is sintered 6 hours；Terminate rear applying argon gas and be cooled to less than 100 DEG C, be warming up to 890 DEG C of insulations carry out one-level tempering for 2 hours, and insulation terminates rear applying argon gas and is cooled to less than 80 DEG C, are warming up to 500 DEG C of insulations 4 Hour carrying out second annealing, insulation terminates rear applying argon gas and is cooled to less than 60 DEG C and comes out of the stove.

48H Sintered NdFeB magnet prepared by method described in embodiment 2 and the 48H sintered NdFeB prepared by comparative example 2 Magnet magnetic property measuring instrument measures, and its performance comparison is as follows:

Classification	Br(KGs)	Hcj(KOe)	(BH)max(MGOe)	Hk/Hcj
					Embodiment 2	13.81	17.23	47.01	0.98
Comparative example 2	13.77	17.35	46.94	0.97

As can be seen from the table above, its magnetic property of 48H magnet prepared by the present embodiment 2 method is prepared than comparative example 2 48H magnet performance is higher, and does not has heavy rare earth metal Dy or Tb in embodiment 2 formula, reduces formulation cost, with Time embodiment 2 total amount of rare earth higher, to production process control requirement lower.

Embodiment described above is not limited to the present invention, for a person skilled in the art, in the spirit of the present invention With within principle, wherein portion of techniques feature is carried out equivalent, should be included within the scope of the present invention.

Claims (5)

1. a high performance sintered neodymium-iron-boron permanent magnet, it is characterised in that: described permanent magnet is by the raw material including following components Make, PrNd:30-32.5wt%, B:0.92-1wt%, Al:0.05-0.8wt%, Cu:0.05-0.3wt%, Co: 0.5-2wt%, Zr:0.1-0.5wt%, Ga:0.05-0.5wt%, Fe surplus.

A kind of high performance sintered neodymium-iron-boron permanent magnet the most according to claim 1, it is characterised in that: described component PrNd In, Pr content 25%, purity is more than 99.5%；Described component Fe is the high purity iron that carbon content is less than 100ppm.

3. a 52M sintered Nd-Fe-B permanent magnet, it is characterised in that: described permanent magnet is by the raw material system including following components Become, PrNd:30.4wt%, B:0.96wt%, Al:0.1wt%, Cu:0.2wt%, Co:0.5wt%, Zr:0.15 Wt%, Ga:0.1wt%, Fe surplus.

4. a 48H sintered Nd-Fe-B permanent magnet, it is characterised in that: described permanent magnet is by the raw material system including following components Become, PrNd:32.0wt%, B:0.94wt%, Al:0.5wt%, Cu:0.2wt%, Co:1.0wt%, Zr:0.15 Wt%, Ga:0.1wt%, Fe surplus.

5. a preparation method for the high performance sintered neodymium-iron-boron permanent magnet as described in claim 1-4 is arbitrary, its feature exists In: comprise the following steps:

1) optimal cast temperature is calculated:

$T=\underset{i=1}{\overset{n}{\&Sigma;}}(E_i*W_i)+k;$

Wherein, T is optimal cast temperature, E_iFor the fusing point of each alloying element, W_iFor the mass fraction of each alloying element, k is Temperature coefficient, 90 DEG C < k < 110 DEG C；

2) dispensing: the raw material of each alloying element is weighed by the mass fraction accounting of its correspondence；

3) melting: by step 2) in raw material be sequentially loaded in rapid hardening furnace crucible by the disentegrated particles such as iron staff, ferro-boron, praseodymium neodymium, Rapid hardening furnace being evacuated to below 5Pa, starts baking material, baking material reaches 10-30 minute, when vacuum is less than 3Pa, and argon filling Gas, to-0.065Mpa, starts melting, continues melting 8-10 minute, molten steel is carried out refine melting after iron staff fusing, Refine smelting time is 2-5 minute, treats that alloy liquid level transfers silvery white to, starts thermometric, when temperature reaches step 1) in During good cast temperature T, start casting, obtain slab；

4) hydrogen is broken: by step 3) slab for preparing puts into and inhales hydrogen in hydrogen crushing furnace to the most saturated, be then heated to 500-600 DEG C and take off Hydrogen, to below 20Pa, obtains coarse powder；

5) powder process: in step 4) prepare coarse powder in add 0.05-0.2% antioxidant, wear in airflow milling volume put down All particle diameter SMD are 2.5-3.0 micron, and particle size distribution ratio X 90/X10 is the fine powder of less than 5.0, add in fine powder 0.05-0.2% lubricant；

6) molding: step 5) fine powder for preparing obtains compact density at magnetic field of press more than the die for molding of 1.5T and is The green compact of 3.6-4.2g/cm3, seal box oxygen content is under nitrogen protection less than 0.05%；

7) isostatic pressed: by step 6) prepare green compact plastic sheeting wrap and put into after Vacuum Package in isostatic pressed press, Under 150-300MPa oil pressure, green density improves further to 4.4-4.8g/cm3；

8) sintering: under nitrogen protection, by step 7) prepare blank peel off vacuum bag and thin film, put into graphite, soon Speed enters stove, is evacuated to 5.0*10^-1Start to warm up after below Pa, be warming up to insulation 3-6 hour when 800-900 DEG C, make true Reciprocal of duty cycle is down to 10^-1Below Pa, is continuously heating to 1000-1100 DEG C and is sintered 2-10 hour；Terminate rear argon filling air cooling But to less than 100 DEG C, being warming up to 860-950 DEG C of insulation and within 1-4 hour, carry out one-level tempering, insulation terminates the cooling of rear applying argon gas To less than 80 DEG C, being warming up to 440-520 DEG C of insulation and within 3-6 hour, carry out second annealing, insulation terminates rear applying argon gas and is cooled to 60 DEG C Hereinafter come out of the stove；Prepare finished product.