阅读说明：本技术 一种高性能永磁铁氧体产品的制备方法 (Preparation method of high-performance permanent magnetic ferrite product ) 是由 曹江平 于 2020-12-22 设计创作，主要内容包括：本发明,采用以锶钡铁氧体干压异性磁细粉为主要原料,添加镧铈钕铁硼(NdFeB)超细磁粉制成的一种高性能永磁铁氧体产品,经检测,性能指标达到：剩磁Br≥4525Gs、内禀矫顽力Hcj≥4163(Oe)、磁能积BH(max)≥4.238MGO,各项性能指标满足了高技术产品应用,且应用前景广阔。本发明的有益效果：1、产品磁性能高、成本相对较低。2、产品性能一致性好,成品合格率高。3、扩大了产品应用领域,节约了稀土资源。4、工艺特殊,产品使用寿命长。(The invention adopts the dry-pressed anisotropic magnetic fine powder of the strontium barium ferrite as the main raw material and adds the lanthanum cerium neodymium iron boron (NdFeB) superfine magnetic powder to prepare a high-performance permanent magnetic ferrite product, and the performance indexes reach the following levels through detection: the remanence Br is more than or equal to 4525Gs, the intrinsic coercive force Hcj is more than or equal to 4163(Oe), and the magnetic energy product BH (max) is more than or equal to 4.238MGO, so that various performance indexes meet the application of high-tech products, and the application prospect is wide. The invention has the beneficial effects that: 1. the product has high magnetic performance and relatively low cost. 2. The product performance consistency is good, and the qualification rate of finished products is high. 3. The application field of the product is enlarged, and the rare earth resource is saved. 4. The process is special, and the service life of the product is long.)

1. The preparation method of the high-performance permanent magnetic ferrite product is characterized by sequentially comprising a raw material optimization process, a formula process, a powder preparation process, a compression process, a sintering process, a grinding process, a polishing process, a sorting process and a magnetic property detection process;

the raw materials selected preferably include Br more than or equal to 4000Gs, Hcj more than or equal to 3100(Oe), BH (max) more than or equal to 3.85MGO, dry-pressed strontium barium ferrite fine powder with the granularity more than or equal to 0.85um, and lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the granularity more than or equal to 10um, wherein the performance of the lanthanum-cerium-neodymium-iron-boron alloy magnetic powder is Br: 5600Gs, Hcj: 9000(Oe), BH (max): 6.5 MGO;

the formula process comprises the steps of preparing the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the weight percentage of 6-20%, and preparing the strontium-barium ferrite dry-pressed anisotropic magnetic fine powder with the balance;

the formula comprises the following steps: adding solid camphor with the weight percentage of 1.1-1.6% and calcium stearate with the weight percentage of 0.25-0.35% into the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the weight percentage of 6-20% according to the formula, and adding the rest of the strontium-barium ferrite dry-pressed anisotropic magnetic fine powder;

secondly, the powder preparation process comprises the following steps: the formula materials in the formula process are gradually and fixedly added into a mixer according to 95% of the mixing capacity of the mixer to be uniformly mixed, the uniformly mixed powder is discharged, and an inner spiral pipe is adopted to feed the materials at a constant speed to a powder scattering machine for scattering the powder;

thirdly, the profiling working procedure comprises the following steps: pressing and molding the product after the powder making process by a hydraulic press, wherein the hydraulic press has a magnetic field anisotropic orientation function, and the pressing process sequentially comprises pressing, magnetizing, pressure maintaining, demagnetizing and demolding;

fourthly, the sintering process comprises the following steps: classifying the formed initial products of the profiling procedure according to specifications, orderly arranging, quantitatively loading the formed initial products into a pot, and then transferring the formed initial products into an electric kiln for sintering and forming, wherein 14 temperature areas are set in an electric kiln, specifically, the 14 temperature areas are as follows, 10 heating areas are set from 80 ℃ to 1240 ℃, 4 cooling areas are set from 1240 ℃ to 80 ℃, and the running time of the temperature areas above 400 ℃ is 2 hours;

fifthly, the grinding process comprises the following steps: transferring different products into a grinder with corresponding tools, guide rails and grinding wheels for customized precise grinding;

sixthly, the polishing process comprises the following steps: and drying, polishing, magnetizing and sorting the ground product in sequence.

2. The preparation method of the high-performance permanent magnetic ferrite product according to claim 1, further comprising a magnetizing step, wherein the magnetizing voltage of a magnetizing machine adopted in the magnetizing step is 600-1250V.

3. The method for preparing a high-performance permanent magnetic ferrite product according to claim 1, wherein in the sorting process, after the product is magnetized, defective products and chips existing in the product are taken out through automatic sorting equipment, and the defective products include damaged products, cracked products, super-thick products, super-wide products, over-ground products, and wear-missing products.

4. The method according to claim 1, wherein the magnetic property detection step is a final magnetic property index of the finished product, and a sampling rate of the product is not less than 5% when a gauss meter is used to measure a magnetic field intensity Gs value on the surface of the product.

Technical Field

The invention relates to a high-performance permanent magnetic ferrite product prepared by dry pressing anisotropic magnetic fine powder with strontium barium ferrite and compositely adding lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder.

Background

The rapid development of the high-technology industry puts forward new requirements for performance indexes of permanent magnetic ferrite products, is used for servo motors of unmanned aerial vehicles, robots and various industrial automation control equipment, and puts forward the requirements for the performance indexes of the used permanent magnetic ferrite: br is more than or equal to 4500Gs, Hcj is more than or equal to 4000(Oe), BH (max) is more than or equal to 4.0MGO, and the performance index of the permanent magnetic ferrite under the process condition of the conventional formula has a large difference, so that a high-price rare earth neodymium iron boron bonded magnet is required to be adopted, and the manufacturing cost of the product is high. The invention adopts strontium barium ferrite dry-pressed anisotropic magnetic fine powder as a main raw material, and adds lanthanum cerium neodymium iron boron NdFeB superfine magnetic powder to prepare a high-performance permanent magnetic ferrite product, and the performance indexes of the high-performance permanent magnetic ferrite product are as follows through detection: the remanence Br is more than or equal to 4525Gs, the intrinsic coercive force Hcj is more than or equal to 4163(Oe), and the magnetic energy product BH (max) is more than or equal to 4.238MGO, so that various performance indexes meet the requirement of high-tech product application, the application prospect is wide, the product manufacturing cost is reduced, and the product additional value is improved.

Aiming at the imperfection of the prior art, the invention provides a preparation method of a ferrite composite magnetic product with high magnetic performance and relatively low product cost. The invention takes the index requirements of the terminal product as the target, adopts the multi-element composite addition technology, greatly reduces the manufacturing cost of the magnetic product, improves the added value of the product, and enlarges the occupancy rate of the low-cost product in the application of the high-technology field. In order to achieve the above object, the present invention adopts the following technical solutions.

Disclosure of Invention

The invention provides a preparation method of a high-performance permanent magnetic ferrite product.

The invention provides the following technical scheme: the preparation method of the high-performance permanent magnetic ferrite product is characterized by sequentially comprising a raw material optimization process, a formula process, a powder preparation process, a compression process, a sintering process, a grinding process, a polishing process, a sorting process and a magnetic property detection process.

The raw materials selected preferably include Br more than or equal to 4000Gs, Hcj more than or equal to 3100(Oe), BH (max) more than or equal to 3.85MGO, dry-pressed strontium barium ferrite fine powder with the granularity more than or equal to 0.85um, and lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the granularity more than or equal to 10um, wherein the performance of the lanthanum-cerium-neodymium-iron-boron alloy magnetic powder is Br: 5600Gs, Hcj: 9000(Oe), BH (max): 6.5 MGO.

The formula process comprises 6-20% by weight of the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder and the balance of the strontium-barium ferrite dry-pressed anisotropic magnetic fine powder.

The formula comprises the following steps: adding 1.1-1.6% by weight of solid camphor, 0.25-0.35% by weight of calcium stearate and the balance of the dry-pressed anisotropic magnetic fine powder of the strontium-barium ferrite into the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the formula of 6-20% by weight.

Secondly, the powder preparation process comprises the following steps: the formula materials in the formula process are fed into a mixer in a gradually fixed amount according to 95% of the mixing capacity of the mixer, the rotating speed of the mixer is set to be 280 revolutions per minute, the mixing time of the mixer is set to be 15 minutes, whether the powder mixed according to the determined mixing rotating speed and time is uniform or not is detected, if the powder is not uniform, the rotating speed and the time are adjusted until the powder is uniformly mixed, the uniformly mixed powder is discharged, the powder is uniformly fed to a powder scattering machine by adopting an inner spiral pipe to scatter the powder, the rotating speed of the scattering machine is 2900 revolutions per minute, the scattering is to scatter the powder to be fluffy and smooth, so that the flowability of the powder is improved, and the powder is scattered immediately and discharged immediately to be transferred to a compression process.

Thirdly, the profiling working procedure comprises the following steps: will the product through the powder process is through hydraulic press forming, hydraulic press is for having the magnetic field orientation function, press forming is the shaping initial product who presses out in the appointed specification mould is equipped with to the press, and the pressing process is in proper order through suppression, magnetization, pressurize, demagnetization, demolding, the pressure of suppressing is 13MP ~ 18MP, the voltage of magnetizing is 1200V, dwell time 2 seconds ~ 4 seconds, shaping initial product: the apparent size meets the tolerance standard, the pressed density reaches 5g/cm3, and the product is soaked in industrial alcohol without bubbles. Quantitative loading into a bowl, putting on a rack and transferring into a sintering process according with requirements.

Fourthly, the sintering process comprises the following steps: and (3) orderly arranging the formed initial products of the profiling procedure according to the batch number and the classified product sizes, and transferring the products to an electric kiln for sintering and forming. The electric kiln is a rotary electric kiln with the length of 40m/360 degrees, 14 temperature areas are set in a temperature area of the electric kiln, the 14 temperature areas are specifically as follows, 10 temperature rising areas are set from 80 ℃ to 1240 ℃, 4 temperature reducing areas are set from 1240 ℃ to 80 ℃, the running time of the temperature area above 400 ℃ is 2 hours, the frequency of the running speed is determined to be 35 HZ-45 HZ according to the size of products, and whether the detection performance and the quality of products discharged from the furnace reach the standard or not. The performance detection is to measure index values such as residual magnetism Br, intrinsic coercive force Hcj, magnetic energy product BH (max) and the like of a product on a magnetic performance calibrator, the detection performance index is to measure the measurement result of a formula product, whether detection data of each index is close to a preset index or not is determined, if so, the formula is returned to, and a powder preparation process is readjusted, and the verification quality is to determine whether the shrinkage ratio of the product is within a tolerance range or not; and (3) judging whether the product is cracked, if so, transversely cracking or longitudinally cracking, adjusting the powder preparation process by transversely cracking, adjusting the temperature of the electric kiln by longitudinally cracking, performing up-to-standard production cyclic sintering after adjustment and adjustment, and turning the discharged product into a grinding process.

Fifthly, the grinding process comprises the following steps: and (4) transferring different products to a grinder with corresponding tools, guide rails and grinding wheels for customized precise grinding. The grinding machine can be of various specifications and models with a single station, a double station and multiple stations, the precise grinding is carried out according to product specifications, the grinding yield can be controlled by adjusting the frequency and the running speed, the running speed is adjusted according to the new and old grinding wheels, and the grinding wheels can be used for multiple back plating and renovation. All the problems of unqualified quality such as inclined grinding, layering, chamfering and reducing heads, high shaft gap, nonuniform grinding of inner and outer R, missing grinding, inconsistent R sizes on two sides and the like are solved, the products are produced after the products are debugged to reach the standard, and the ground qualified products are shifted to polishing, magnetizing and sorting procedures.

Sixthly, the polishing process comprises the following steps: and drying, polishing, magnetizing and sorting the ground product in sequence, wherein the drying is to dry the ground product on a dryer.

Polishing is carried out on the dried product on a polishing machine, the polishing treatment is carried out by adding a small amount of waste mechanical oil into the wood sphene, the dried product is added into a polishing machine, the polishing machine is a high-frequency vibration type device, the high frequency is a vibration polishing mode capable of adjusting the frequency, the vibration polishing time is determined according to the polishing degree of the product, and the polishing degree is determined by requiring that the surface of the product is smooth, the oil stain is not adhered, and the wood sphene is not adhered, and is generally determined to be 15-20 minutes.

The preparation method further comprises a magnetizing procedure, wherein a magnetizing machine adopted in the magnetizing procedure is full-automatic magnetizing equipment, the full-automatic magnetizing equipment is provided with a vibration blanking plate, a plurality of product intensive magnetizing tools and an automatic blanking control device, the magnetizing voltage is 600-1250V, the magnetizing equipment can adopt two modes of saturated magnetizing and unsaturated magnetizing according to customer requirements, magnetizing products are divided into S poles and N poles, and the two magnetic pole products are respectively stored in equal quantity.

The sorting process is characterized in that after the products are magnetized, the stored defective products are taken out in an automatic mode through automatic sorting equipment, the defective products are damaged, cracked, super-thick, super-wide, over-ground, missed-ground and the like, and the sorted products are orderly arranged and quantitatively packaged.

The magnetic property detection process is a final magnetic property index of a finished product, a gauss meter is adopted to determine a Gs value of the magnetic field intensity on the surface of the product, the sampling and detecting proportion of the product is not lower than 5%, and the requirement on the central Gs value of the product is satisfied.

The invention has the following beneficial effects by adopting the technical scheme.

1. The product has high magnetic performance and relatively low cost. According to the product formula, the neodymium iron boron permanent magnetic powder, the strontium carbonate, the lanthanum oxide and the like are properly added, so that various performance indexes of the permanent magnetic ferrite are improved, and the detection is as follows: br: 4525Gs, Hcj: 4136(Oe), bh (max): 4.238MGO, the performance index is only in the same product at present, the formula cost of the product is more than the cost of the common ferrite product, but the formula cost is far lower than the cost of the bonded neodymium iron boron and sintered neodymium iron boron products, and the added value of the product is improved.

2. The product performance consistency is good, and the qualification rate of finished products is high. The product has consistent surface magnetic performance and appearance geometric dimension through process optimization and parameter adjustment of procedures such as formula, powder making, compression, sintering, grinding and the like, the product percent of pass is improved to 98 percent, the product percent of pass exceeds the index of 95 percent in the same industry, and the gross profit rate of the product is improved.

3. The application field of the product is enlarged, and the rare earth resource is saved. In the high and new technology, the servo motor used for unmanned aerial vehicles, robots and various industrial automation control equipment is included, the servo motor does not need very high magnetic performance such as indexes of remanence, intrinsic coercive force and magnetic energy product, but the performance index of the common ferrite product can not be met, in view of the above, the invention takes high-end application as an entry, takes the magnetic performance index reaching or exceeding Br more than or equal to 4500Gs, Hcj more than or equal to 4000(Oe) and BH (max) more than or equal to 4.0MGO as targets, and reaches through various magnetic performances by testing: br: 4525Gs, Hcj: 4163(Oe), bh (max) 4.238MGO, very good reliability for the application of high new technology products, while saving valuable rare earth resources.

4. The process is special, and the service life of the product is long. The lanthanum-cerium-neodymium-iron-boron superfine permanent magnet powder added in the formula of the product is subjected to oxidation resistance treatment and high-temperature thermal demagnetization treatment. The anti-oxidation treatment is through high wet processing, high temperature thermal demagnetization handles and carries out accurate control by temperature change to the superfine permanent-magnet powder of lanthanum cerium neodymium iron boron and does the demagnetization, the superfine permanent-magnet powder of lanthanum cerium neodymium iron boron is within average particle size D50/10um, it obtains to be a special grinding method within average particle size D50/10um, and the effectual mixture of having solved the superfine magnetic powder of lanthanum neodymium cerium iron boron and strontium barium magnetism farine of above technology, and the ferrite product of output need not do the anticorrosion treatment, product long service life.

Detailed Description

The invention is further described below in conjunction with the specific embodiments.

The preparation method of the high-performance permanent magnetic ferrite product is characterized by sequentially comprising a raw material optimization process, a formula process, a powder preparation process, a compression process, a sintering process, a grinding process, a polishing process, a sorting process and a magnetic property detection process.

The raw materials selected preferably include Br more than or equal to 4000Gs, Hcj more than or equal to 3100(Oe), BH (max) more than or equal to 3.85MGO, dry-pressed strontium barium ferrite fine powder with the granularity more than or equal to 0.85um, and lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the granularity more than or equal to 10um, wherein the performance of the lanthanum-cerium-neodymium-iron-boron alloy magnetic powder is Br: 5600Gs, Hcj: 9000(Oe), BH (max): 6.5 MGO.

The formula process comprises 6-15% by weight of the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder and the balance of the strontium-barium ferrite dry-pressed anisotropic magnetic fine powder.

The formula comprises the following steps: adding 1.1-1.2% by weight of solid camphor, 0.25-0.30% by weight of calcium stearate and the balance of the dry-pressed anisotropic magnetic fine powder of the strontium-barium ferrite into the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the formula of 6-15% by weight.

Secondly, the powder preparation process comprises the following steps: the formula materials in the formula process are fed into a mixer in a gradually fixed amount according to 95% of the mixing capacity of the mixer, the rotating speed of the mixer is set to be 280 revolutions per minute, the mixing time of the mixer is set to be 15 minutes, whether the powder mixed according to the determined mixing rotating speed and time is uniform or not is detected, if the powder is not uniform, the rotating speed and the time are adjusted until the powder is uniformly mixed, the uniformly mixed powder is discharged, the powder is uniformly fed to a powder scattering machine by adopting an inner spiral pipe to scatter the powder, the rotating speed of the scattering machine is 2900 revolutions per minute, the scattering is to scatter the powder to be fluffy and smooth, so that the flowability of the powder is improved, and the powder is scattered immediately and discharged immediately to be transferred to a compression process.

Thirdly, the profiling working procedure comprises the following steps: will the product through the powder process is through hydraulic press forming, hydraulic press is for having magnetic field opposite sex orientation function, press forming is the shaping initial product who presses out in the appointed specification mould is equipped with to the press, and the pressing process is in proper order through suppression, magnetization, pressurize, demagnetization, demolding, the pressure of suppressing is 13MP-18MP, the voltage of magnetizing is 1200V, dwell time 5 seconds, shaping initial product: the apparent size meets the tolerance standard, the pressed density reaches 5g/cm3, and the product is soaked in industrial alcohol without bubbles. Quantitative loading into a bowl, putting on a rack and transferring into a sintering process according with requirements.

Fourthly, the sintering process comprises the following steps: and (3) orderly arranging the formed initial products of the profiling procedure according to the batch number and the classified product sizes, and transferring the products to an electric kiln for sintering and forming. The electric kiln is a rotary electric kiln with the length of 40m/360 degrees, 14 temperature areas are set in a temperature area of the electric kiln, the 14 temperature areas are specifically as follows, 10 temperature rising areas are set from 80 ℃ to 1240 ℃, 4 temperature reducing areas are set from 1240 ℃ to 80 ℃, the running time of the temperature area above 400 ℃ is 2 hours, the frequency of the running speed is determined to be 25 HZ-45 HZ according to the size of products, and the detection performance index and the quality verification of products discharged from the furnace reach the standard. The performance detection is to measure index values such as residual magnetism Br, intrinsic coercive force Hcj, magnetic energy product BH (max) and the like of a product on a magnetic performance calibrator, the detection performance index is to measure the measurement result of a formula product, whether detection data of each index is close to a preset index or not is judged, if so, the formula is returned to the formula, and the powder preparation process is readjusted, and the calibration quality is as follows: whether the shrinkage ratio of the product is within the tolerance range or not, whether the product cracks, if so, whether the product cracks transversely or longitudinally, the transverse cracking needs to adjust the powder making process, the longitudinal cracking needs to adjust the temperature of the electric kiln, the adjustment and the adjustment are finished, the product reaches the standard and is sintered circularly, and the product discharged from the furnace is transferred to the grinding process.

Fifthly, the grinding process comprises the following steps: and (4) transferring different products to a grinder with corresponding tools, guide rails and grinding wheels for customized precise grinding. The grinding machine can be of various specifications and models with a single station, a double station and multiple stations, the precise grinding is carried out according to product specifications, the grinding yield can be controlled by adjusting the frequency and the running speed, the running speed is adjusted according to the new and old grinding wheels, and the grinding wheels can be used by plating and refurbishing more times. The grinding machine is used for grinding the inner side and the outer side of the grinding wheel, and the grinding machine is used for grinding the inner side and the outer side of the grinding wheel.

Sixthly, the polishing process comprises the following steps: and drying, polishing, magnetizing and sorting the ground product in sequence, wherein the drying is to dry the ground product on a dryer.

Polishing is carried out on the dried product on a polishing machine, the polishing treatment is carried out by adding a small amount of waste mechanical oil into the wood sphene, the dried product is added into a polishing machine, the polishing machine is a high-frequency vibration type device, the high frequency is a vibration polishing mode capable of adjusting the frequency, the vibration polishing time is determined according to the polishing degree of the product, and the polishing degree is determined by requiring that the surface of the product is smooth, the oil stain is not adhered, and the wood sphene is not adhered, and is generally determined to be 15-20 minutes.

The preparation method further comprises a magnetizing procedure, wherein a magnetizing machine adopted in the magnetizing procedure is full-automatic magnetizing equipment, the full-automatic magnetizing equipment is provided with a vibration blanking tray, a plurality of product intensive magnetizing tools and an automatic blanking control device, the magnetizing voltage is 600-1200V, the full-automatic magnetizing equipment can adopt a saturated magnetizing mode and an unsaturated magnetizing mode according to customer requirements, the magnetizing products are magnetized by distinguishing S poles and N poles, and the two magnetic pole products are respectively stored in equal quantity.

The sorting process is to carry out sorting and taking out on defective products and chips stored in the products through automatic sorting equipment after the products are magnetized, the defective products are damaged, cracked, super-thick, super-wide, over-ground, missed-ground products and the like, and the sorted products are orderly arranged and quantitatively packed.

The magnetic property detection process is a final magnetic property index of a finished product, a gauss meter is adopted to determine a Gs value of the magnetic field intensity on the surface of the product, the sampling and detecting proportion of the product is not lower than 5%, and the requirement on the central Gs value of the product is satisfied.

The second embodiment is a preparation method of a high-performance permanent magnetic ferrite product, which is characterized by sequentially comprising a raw material optimization process, a formula process, a powder preparation process, a compression process, a sintering process, a grinding process, a polishing process, a sorting process and a magnetic property detection process.

The raw materials selected preferably include Br more than or equal to 4000Gs, Hcj more than or equal to 3100(Oe), BH (max) more than or equal to 3.85MGO, dry-pressed strontium barium ferrite fine powder with the granularity more than or equal to 0.85um, and lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the granularity more than or equal to 10um, wherein the performance of the lanthanum-cerium-neodymium-iron-boron alloy magnetic powder is Br: 5600Gs, Hcj: 9000(Oe), BH (max): 6.5 MGO;

the formula process comprises 10-20% by weight of the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder and the balance of the strontium-barium ferrite dry-pressed anisotropic magnetic fine powder.

The formula comprises the following steps: adding 1.4-1.6% by weight of solid camphor, 0.30-0.35% by weight of calcium stearate and the balance of the dry-pressed anisotropic magnetic fine powder of the strontium-barium ferrite into the 10-15% by weight of the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder according to the formula.

Secondly, the powder preparation process comprises the following steps: and (3) feeding the formula materials of the formula procedure into a mixer according to 95% of the mixing capacity of the mixer in a fixed amount one by one, uniformly mixing, discharging the uniformly mixed powder, and feeding the powder to a powder scattering machine at a constant speed by adopting an inner spiral pipe for scattering the powder.

Thirdly, the profiling working procedure comprises the following steps: and pressing and molding the product after the powder preparation process by using a hydraulic press, wherein the hydraulic press has a magnetic field anisotropic orientation function, and the pressing process sequentially comprises pressing, magnetizing, pressure maintaining, demagnetizing and demolding.

Fourthly, the sintering process comprises the following steps: and classifying the sizes of the molded primary products in the profiling procedure, then orderly arranging the products, and transferring the products to an electric kiln for sintering and molding. The electric kiln temperature zone is set with 14 temperature zones, wherein the 14 temperature zones are specifically as follows, 10 heating zones are set from 80 ℃ to 1240 ℃, 4 cooling zones are set from 1240 ℃ to 80 ℃, and the running time of the temperature zone above 400 ℃ is 2 hours.

Fifthly, the grinding process comprises the following steps: and (4) transferring different products to a grinder with corresponding tools, guide rails and grinding wheels for customized precise grinding.

Sixthly, the polishing process comprises the following steps: and drying, polishing, magnetizing and sorting the ground product in sequence.

The preparation method further comprises a magnetizing procedure, wherein the magnetizing voltage of a magnetizing machine adopted in the magnetizing procedure is 700-1250V.

The sorting process is to sort and take out defective products and fragments stored in the products through automatic sorting equipment after the products are magnetized, wherein the defective products are damaged, cracked, super-thick, super-wide, over-ground, ground and missed ground products and the like.

The magnetic property detection procedure is to measure the final magnetic property index of the finished product by adopting a gaussmeter to measure the magnetic field intensity Gs value on the surface of the product, and the sampling rate of the product is not lower than 5%.

The third embodiment is a preparation method of a high-performance permanent magnetic ferrite product, which is characterized by sequentially comprising a raw material optimization process, a formula process, a powder preparation process, a compression process, a sintering process, a grinding process, a polishing process, a sorting process and a magnetic property detection process.

The raw materials selected preferably include Br more than or equal to 4000Gs, Hcj more than or equal to 3100(Oe), BH (max) more than or equal to 3.85MGO, dry-pressed fine powder of strontium barium ferrite with the granularity more than or equal to 0.85um, and lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the granularity more than or equal to 10um, wherein the performance of the lanthanum-cerium-neodymium-iron-boron alloy magnetic powder is Br: 5600Gs, Hcj: 9000(Oe), BH (max): 6.5 MGO;

the formula process comprises 6-20% by weight of the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder and the balance of the strontium-barium ferrite dry-pressed anisotropic magnetic fine powder.

The formula comprises the following steps: adding solid camphor accounting for 1.2-1.5% by weight percentage and calcium stearate accounting for 0.30-0.34% by weight percentage into the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder with the formula accounting for 8-11% by weight percentage, and dry-pressing the anisotropic magnetic fine powder by the strontium-barium ferrite for the rest.

Secondly, the powder preparation process comprises the following steps: and (3) feeding the formula materials of the formula procedure into a mixer according to 95% of the mixing capacity of the mixer in a fixed amount one by one, uniformly mixing, discharging the uniformly mixed powder, and feeding the powder to a powder scattering machine at a constant speed by adopting an inner spiral pipe for scattering the powder.

Thirdly, the profiling working procedure comprises the following steps: and pressing and molding the product after the powder preparation process by using a hydraulic press, wherein the hydraulic press has a magnetic field anisotropic orientation function, and the pressing process sequentially comprises pressing, magnetizing, pressure maintaining, demagnetizing and demolding.

Fourthly, the sintering process comprises the following steps: and classifying the sizes of the molded primary products in the profiling procedure, then orderly arranging the products, and transferring the products to an electric kiln for sintering and molding. The electric kiln temperature zone is set with 14 temperature zones, wherein the 14 temperature zones are specifically as follows, 10 heating zones are set from 80 ℃ to 1240 ℃, 4 cooling zones are set from 1240 ℃ to 80 ℃, and the running time of the temperature zone above 400 ℃ is 2 hours.

Fifthly, the grinding process comprises the following steps: and (4) transferring different products to a grinder with corresponding tools, guide rails and grinding wheels for customized precise grinding.

Sixthly, the polishing process comprises the following steps: and drying, polishing, magnetizing and sorting the ground product in sequence.

The preparation method further comprises a magnetizing procedure, wherein the magnetizing voltage of a magnetizing machine adopted in the magnetizing procedure is 800-1000V.

The sorting process is to carry out sorting and taking out on defective products and fragments stored in the products through automatic sorting equipment after the products are magnetized, wherein the defective products are broken, cracked, super-thick, super-wide, over-ground, missed-ground products and the like.

The magnetic property detection procedure is to measure the final magnetic property index of the finished product by adopting a gaussmeter to measure the magnetic field intensity Gs value on the surface of the product, and the sampling rate of the product is not lower than 5%.

And (4) conclusion: the third embodiment is the best.

1. 8-11% of the lanthanum-cerium-neodymium-iron-boron alloy superfine magnetic powder according to the weight percentage of the formula, 1.1-1.6% of solid camphor (DAB-8 standard), 0.25-0.35% of calcium stearate according to the weight percentage, and the balance of strontium-barium ferrite dry-pressed anisotropic magnetic fine powder.

2. The rotating speed of the mixer is 280 rpm, and the mixing time of the mixer is 15 minutes, so that the powder uniformity is high.

3. The rotating speed of the scattering machine is 2900 revolutions per minute, and the scattered powder is fluffy, smooth and good in fluidity; immediately scattering, immediately discharging and transferring into a pressing type region to be transferred for 24 hours, then transferring into a pressing type process, completely absorbing the binder by the powder, and having good pressing property.

4. The pressing process is carried out through pressing → magnetizing → pressure maintaining → demagnetizing → demoulding, the pressing pressure is 13MP-18MP, the magnetizing voltage is 1200V, the pressure maintaining time is 5 seconds, and the molded initial product: the apparent size meets the tolerance standard, the pressed density reaches 5g/cm3, and the product is soaked in industrial alcohol without bubbles.

5. The remanence of the product is Br by detection: 4.255Gs, intrinsic coercivity Hcj: 4163(Oe), magnetic energy product BH (max): 4.238MGO, quality by assay: the product shrinkage ratio is within the tolerance range, no cracks exist, and the performance index of high-tech product application is met.

6. The product is ground and shaped, the quality disqualification such as oblique grinding, layering, chamfering large and small heads, shaft height gap, non-uniform grinding of inner and outer R, missing grinding, inconsistent R sizes at two sides and the like does not occur, and the product is qualified after the quality test of the product.

7. The sampling inspection proportion of the product is 5 percent, the central value of the surface magnetic field intensity is 1150Gs, and the product is uniform in distribution and good in consistency.