注射成形粘结钕铁硼磁体复合粉研究

磁体的注射成形是一种高效生产的近净成形技术。为了制备出具有较好综合性能的注射成形粘结钕铁硼永磁材料,研究了粘结剂对注射成形磁体的磁性能、加工性能及力学性能的影响;分析了硅烷系列的偶联剂、复合润滑剂和抗氧剂等添加剂对注射成形磁体性能的影响。结果表明,用MQP-B快淬钕铁硼磁粉和尼龙12粘结剂制备出了剩余磁感应强度为0.539 T,磁感矫顽力为345.37 k A/m,内禀矫顽力为681.02 k A/m,最大磁能积为47.37 k J/m3的注射成形钕铁硼磁体。     

模压成形各向异性NdFeB粘结磁体性能研究

采用模压成形方法制备各向异性粘结NdFeB磁体,主要研究了粉末粒度以及取向磁场强度对粘结磁体磁性能和力学性能的影响.试验结果表明,随着磁粉粒度的减小,粘结磁体的剩磁有所增加,但矫顽力下降明显.随着取向磁场强度的增大,粘结磁体剩磁进一步提高,各向异性明显;粘结磁体密度及抗压强度随磁粉粒度的减小略有提高.经粒度配比后制备的粘结磁体获得了较高的磁性能和抗压强度,其B_r、H_(ci)及σ_(bc)分别为0.81T、828kA/m及204MPa.     

注射成形粘结钕铁硼/铁氧体复合磁体的研究

对注射成形粘结Nd-Fe-B/铁氧体复合磁体进行了深入的研究。实验结果表明：随着铁氧体磁粉的加入，复合磁体的磁性能虽略有降低，但其力学性能及热稳定性均有大幅度改善，特别是在铁氧体含量为87%（质量分数时），复合磁体内禀矫顽力温度系数为零，不同磁粉间静磁场的存在，使得复合磁体在铁氧体含量低于70%（质量分数）时，其磁性能大于平均值，而大于70%（质量分数）时则小于平均值。     

Manufacturing of Injection-Molded NdFeB Magnet with (BH)max111 kJ · m-3

The bonded NdFeB magnets prepared by injection molding meet with the development tendency of the magnet in small volume, light weight and high performance ,and have a good prospect.In this paper, a modified nylonbased binder was developed for powder injection molding of NdFeB bonded magnets.The effects of pretreatment of NdFeB anisotropic magnetic powder produced with HDDR processing on the anti-oxidation behaviors of powder and the final magnetic properties of the molded bonded magnets were studied.The optimal powder loading of 65 vol% was achieved with the modified binder.It was found that the properties of the bonded magnets were mainly affected by the powder surface pretreatment and the intensity of the applied alignment magnetic field during injection molding for a certain powder.Bonded magnets with remanence of 0.820 T, intrinsic coercivity of 1140.3 kA· m-1 and maximum energy product of 111 kJ · m-3 were produced with the optimal processing.     

Study on Fabrication Process of Anisotropic Injection Bonded Nd-Fe-B Magnets

This study is on the injection molding process for the fabricating anisotropic Nd-Fe-B bonded magnets. The effects of powder loading, particle size of the magnetic powder, polymer binder and the fabricating process on the magnetic and the mechanical properties of anisotropic Nd-Fe-B magnets were investigated. The proper powder loading, particle size and binder are 60%(vol%), 75–106 μm and PA 1010, respectively. The optimum condition for good magnetic properties of anisotropic injection bonded Nd-Fe-B magnets is mixing the binder and the chemicals in the temperature between 205–215 °C, injection temperature of 265 °C, the injection pressure of 5–6 MPa, the press time of 5 second, and molding temperature of 80 °C. The magnetic properties of anisotropic bonded Nd-Fe-B magnets made in above conditions from d-HDDR powder were: B_r=0.72 T, _iH_c=983 kA/m, (BH)_max=75 kJ/m^c.     

注射成型粘结NdFeB永磁体

介绍了粘结永磁体的制备工艺,快淬NdFeB磁粉,HDDR磁粉及粘结磁体的磁性.提出了目前注射制备NdFeB磁体的技术开发要点.     

Anisotropic NdFeB/SmCoCuFeZr composite bonded magnet prepared by warm compaction process

Anisotropic NdFeB/SmCoCuFeZr composite bonded magnets were prepared by warm compaction process. The effects of adding SmCoCuFeZr magnetic powder on the properties of anisotropic bonded NdFeB magnet were investigated in this work. The results show that, both magnetic properties and temperature stability of the bonded magnet can be improved by adding fine SmCoCuFeZr magnetic powder. In the present study, the optimal content of SmCoCuFeZr magnetic powder was about 20 wt.%, in this case, the Br, Hcj, and(BH)maxof the NdFeB/SmCoCuFeZr composite magnet achieved 0.943 T, 1250 kA/m, and168 kJ/m~3, respectively.     

Progress of Sm-Fe-N Anisotropic Magnets

A reduction and diffusion method (R/D) is used to make a mother alloy of Sm-Fe-N anisotropic magnets. Reduction of 0.5wt% of samarium content compared to the conventional powder increases magnetization. Milling condition and surface treatment improve the squareness of demagnetization curve, the aging property and the heat resistance. The maximum energy product of 292 kJ/m³ is obtained with the powder. High coercive force is maintainable even if the powder is exposed for 300h in 80 °C 90%RH. The maximum energy product of 141 kJ/m³ is obtained with an injection molded anisotropic magnet. The aging property estimated by irreversible flux loss is comparable to the conventional MQP-B magnets. The heat resistance temperature (T_−5%) at which die initial irreversible flux loss becomes −5% is 125-more than 150 °C for Sm-Fe-N magnets and 150–170 °C for hybrid magnets. The magnetic properties of bonded HDDR Nd-Fe-B magnet were improved by substituting for Nd-Fe-B powder with Sm-Fe-N powder. A new technology to make anisotropic bonded Sm-Fe-N thin cylinder magnets by an injection molding using unsaturated polyester (UP) resin was developed.     

粉末注射成形在永磁材料中的应用

讨论了粉末注射成形在粘结磁体生产中的应用和烧结磁体研究开发的现状。介绍了注射成形用磁粉的多种制造方法,常用注射成形粘结磁体和杂合磁体的基本性能及应用。分析了影响注射成形磁体性能的技术关键。指出了粉末注射成形在生产低成本、高精度、高性能磁体的技术优势。     

注射成形钕铁硼粘结磁体研究的现状及前景

论述了注射成形钕铁硼粘结磁体的特点及发展趋势，分析了其生产工艺中的四个关键因素。包括磁粉，粘结剂与耦联剂，注射过程，充磁过程，并对这四个关键因素的研究状况作了综合评述，认为今后对注射成形钕铁硼粘结磁体的研究开发将集中在四个主要的方面。     

注射成形制备NdFeB粘结磁体

为了制备出高性价比的粘结NdFeB注射磁体，本文系统的研究了粘结剂、添加剂的含罱以及磁粉装载量对注射磁体的加工性能、磁性能等的影响规律，并从微观上揭示了其机理。本文采用低成本的陶广：快淬钕铁硼磁粉和国产尼龙6粘结剂制备出了磁性能Br为0．5158T、Heb为321kA／m、Hcj为730kA／m和（BH）max为40kl／m^3的注射磁体，其性能与日本Mate公司的RNI-50产品性能相当，而价格却低得多.     

Developments in Melt Spun Powders for Permanent Magnets

Bonded and fully-dense magnets prepared from melt-spun RE₂Fe₁₄B-type powders continue to find new applications in consumer electronics, automotive and industrial motors. The unique nanostructure of these materials promotes high magnetic performance, environmental stability and near-net shape formability. This article reviews the various types of melt spun powder from a compositional and microstructural standpoint. The powder with best overall performance and stability for bonded magnets appears to be the RE₂Fe₁₄B single phase type. Additional corrosion resistance can be achieved by coating the powder with an organic micro-dispersion prior to molding. Regarding higher performance fully dense magnets, multi-phase RE₂Fe₁₄B/RE melt spun powder offers a highly flexible precursor for hot forming near-net shape isotropic and anisotropic magnets. The composition of the melt spun powder along with the degree of hot deformation can be tailored to provide a range of magnetic properties from these types of magnet.     

NdFeB粘结磁体加工性能

应用高压毛细管流变仪和HAAKE转矩流变仪，研究了粘结剂尼龙．6质量分数10％时的NdFeB粘结磁体流变和加工性能。结果表明：NdFeB粘结磁性材料的喂料体系的流动为非牛顿型假塑性液体，具有超高的熔体粘度；润滑剂能有效地降低喂料流动粘度，改善加工条件；而偶联剂会恶化其加工性能；磁粉的粒度分布对喂料的粘度和加工性能有明显的影响。本实验结果可为NdFeB粘结磁体注射、挤出成型的工艺参数确定、模具和机械设计以及加工质量的控制等提供技术依据。     

粘结钕铁硼磁环在高性能永磁式步进电动机上的应用

钕铁硼粘结磁体是一种将钕铁硼磁粉与高分子树脂或塑料或低熔点合金及各种添加剂均匀混合,用模压、挤出或注射成形等方法制成的复合永磁材料。国内外对其机理的研究已比较深入,本课题仅就钕铁硼粘结磁体特别是应用于高性能永磁式步进电动机的粘结钕铁硼多极磁环的制备工艺中的关键问题进行了研究,内容包括：（１）专用粘结剂的选择;（２）磁粉选择;（３）薄壁磁环自动压制成形;（４）表面防锈处理方式的选择;（５）多极充磁;（６）磁环转子整体注射成形。结果表明：在解决了上述关键工艺问题后,粘结钕铁硼多极磁环已批量应用于高性能永磁式步进电动机,替代进口或使原有的电机升级换代     

Preparation and characterization of sodium silicate/epoxy resin composite bonded Nd-Fe-B magnets with high performance

As an organic binder for bonded Nd-Fe-B magnets, epoxy resin(EP) has poor heat resistance but good moisture resistance, while sodium silicate(SS) has poor moisture absorption but better heat resistance and corrosion resistance. In order to improve high temperature stability and decrease moisture absorption of bonded Nd-Fe-B magnets, EP/SS composites were applied as the binder to prepare bonded Nd-Fe-B magnets. The magnetic properties, moisture absorption, corrosion resistance, compressive strength and microstructure of composite bonded magnets were investigated. The results show that EP/SS bonded magnets can obtain excellent magnetic properties at room temperature, and even useable magnetic properties a thigh temperature environments at 200°C. EP/SS composite binder effectively improves heat resistance and corrosion resistance of bonded Nd-Fe-B magnets, and reduces the hygroscopic properties. The molecule of sodium silicateis rigid and keeps it original shape at high temperature environments. In addition, SS in composite binder improves the mobility of the magnetic powders during the pre-pressing process, which makes the magnetic powders attain a more regular structure. These two factors will increase the mechanical properties. Moreover, sodium silicate in the composite binder can also cover the surfaces protecting the magnetic powders from oxidation and corrosion. EP in composite binder can cover SS surface to reduce the water absorption of SS as epoxy is a hydrophobic material. The EDX analysis shows that the composite binder has accumulated in the gaps of the magnet powders, which not only improves heat resistance and corrosion resistance, but also increases the mechanical properties. Therefore, EP/SS composite binder endows bonded Nd-Fe-B magnets excellent comprehensive properties.     

Nd-Fe-B永磁材料的粉末注射成形技术

介绍了目前采用的几种粉末注射成形用Nd-Fe-B磁粉的制备方法及特点;讨论了粘结剂、改性剂及磁场取向对注射成形Nd-Fe-B粘结剂磁体和烧结磁体最终磁性能的影响;指出了注射成形Nd-Fe-B磁体的现在以及潜在的应用市场。在此基础上,指出了今后开展研究工作的方向。     

注射成形钕铁硼粘结磁体研究的现状及前景

论述了注射成形钕铁硼粘结磁体的特点及发展趋势,分析了其生产工艺中的4个关键因素,包括磁粉、粘结剂与藕联剂、注射过程、充磁过程,并对这4个关键因素的研究状况作了综合评述,认为今后注射成形钕铁硼粘结磁体的研究开发将主要集中在以下4个方面研究:各向异性粉末和各向异性粘结磁体,研发合适的粘结体系及注射成形工艺参数,开发磁能积更高的磁体,开发耐热钕铁硼粘结磁体。     

粉末注射成形在软磁材料中的应用

介绍了粉末注射成形在粘结软磁、烧结软磁生产中的应用、研究开发状况。指出粉末注射成形是能够实现低成本生产新性能、新功能的磁体制造技术,应该利用注射成形技术发挥磁性元器件结构功能一体化设计、制造的优势。     

FeCuNbSiB粘结磁体的制备及磁性能研究

通过2种途径将熔体快淬法制得的FeCuNbSiB非晶薄带制成环状粘结磁体。一是将非晶薄带进行晶化处理,再将晶化后的薄带粉碎成不同粒度的粉末,然后与粘结剂相混合制成粘结磁体。二是将非晶薄带直接粉碎成不同粒度的粉末,再将此粉末进行晶化处理,将晶化后的磁粉与粘结剂相混合制成粘结磁体。分析了磁粉粒度和模压压力对粘结磁体性能的影响。并对两种粘结磁体的性能进行比较。结果表明,第一种方法制备的粘结磁体的性能优于第二种。     

Effect of Particle Size and Distribution of Rapidly Quenching NdFeBMagnetic Powder on Magnetic Properties of PolymerBonded NdFeBPermanent Magnet

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