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.     

工艺参数对注射成形各向异性粘结NdFeB磁体性能的影响

研究了注射温度、模具温度、注射压力及注射速度对注射成形各向异性粘结NdFeB磁体的磁性能及力学性能的影响，并分析了其原因。结果表明：注射温度及模具温度对磁体磁性能影响较大，而注射压力则对磁体的抗压强度影响较大。在最佳的注射参数下，获得了最大磁能积和抗压强度分别为90kJ／m^3及130MPa的高性能粘结磁体。     

压机对粘结NdFeB磁体质量的影响

模压成形是粘结NdFeB磁体制造的最主要方法。分析了粘结NdFeB磁体的特点;在实验研究和大量生产实践的基础上,介绍了模具结构、压机结构和压制成形动作对磁体质量的重要影响;总结了控制粘结NdFeB磁体质量的关键技术。     

温压成形制备d-HDDR各向异性钕铁硼粘结磁体的研究

研究了d-HDDR各向异性NdFeB粘结磁体温压成形过程中粘结剂、润滑剂、成形压力对磁体磁性能的影响.通过温压机理的分析,发现温压工艺的温度主要决定于粘结剂体系的黏度、软化点和凝胶时间.添加适量的润滑剂,可减小粉末间及粉末与模壁间的摩擦力,有利于提高磁体的取向度.增加成形压力能明显提高磁体的密度,从而改善磁体的磁性能.采用合适的温压工艺,可获得取向度高(94%)、磁性能优异[BHmax=159.96 kJ/m3(20.17 MG-Oe)]的粘结钕铁硼永磁体.     

粉末粒度对注射粘结磁体性能的影响

实验分析了粉末粒度对制得的注射粘结磁体密度、取向度和磁性能的影响，得出了磁粉粒径太大和太小均不利于磁体磁性能的提高的结论．同时，通过搭配不同比例的粉末，可以提高磁体的装载量，从而达到提高磁性能的目的．     

粘结磁体助剂对模压成型NdFeB粘结磁体性能的影响

采用模压设备制备了NdFeB粘结磁体,并研究了粘结助剂(粘结剂和偶联剂)对快淬NdFeB粘结磁体力学性能,包括密度和抗压强度以及磁性能的影响.研究结果表明,添加偶联剂可以提高粘结磁体的性能.使用E-51环氧树脂粘结剂所获得的磁体密度、剩磁、矫顽力、最大磁能积以及抗压强度比用E-44粘结剂的磁体性能要高.随着粘结剂含量的增加,磁体的密度在逐渐降低,磁体的抗压强度在不断变大.而剩磁随着粘结剂含量的增加在不断下降.对矫顽力这个性能来说,1.5%的粘结剂含量为最佳用量.     

粘结稀土钕铁硼永磁体模压成形工艺的研究

本文针对模压成型的快淬稀土钕铁硼粘结永磁体,着重研究了粘结剂的种类,粘结剂的含量、模压压力等参数对NdFeB粘结磁体磁性能和机械性能的影响,为粘结NdFeB磁体的应用做了技术上的探讨。     

2种NdFeB粉末的混炼研究

采用快淬法和雾化法制得的2种不同形貌的NdFeB磁粉,以尼龙12作粘结剂,研究了注射成形粘结磁体的混炼过程。分析了2种磁粉的形貌与粉末粒度及其分布,对混合料的粉末临界充填率、均匀度、流变特性的影响,以及混炼温度对磁性能的影响。     

ZrN掺杂对热压-热变形制备钕铁硼磁体磁性能和电阻率的影响

以NdFeB粉和ZrN粉为原料,通过真空热压烧结与热压变形,制备ZrN掺杂量(质量分数)为0～5%的NdFeB磁体,研究Zr N掺杂对NdFeB磁体密度、电阻率与磁性能的影响。结果表明,随w(ZrN)增大,热压烧结态磁体的密度先增加后降低;热压变形后的NdFeB磁体,中心部位的磁性能最佳,沿径向逐渐变差,并且随w(ZrN)增加,磁体的电阻率增大,但磁性能整体下降较明显。w(ZrN)为1%的热变形磁体具有较好的磁性能,剩磁为1.362T,矫顽力为865.5 kA/m,最大磁能积为349.6 kJ/m3,同时电阻率达到250μΩ·cm,比未掺杂NdFeB磁体的电阻率(230μΩ·cm)提高8.7%,达到作为稀土永磁电机中转子的使用要求。     

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。     

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.     

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

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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。     

Investigation on the Moldability of HDDR NdFeB Bonded Magnet Prepared by Compression Molding Method

The phenomenon of uneven density distribution is inevitable in the process of preparing bonded magnets with complicated shape or with large geometric size by compression molding due to the friction among magnetic powder grains and between magnetic powder and the die wall, which reduces the pressure along the compression direction. In order to improve the density distribution homogeneity, the thin-wall rings with composition of HDDR NdFeB prepared by compression molding were selected as the investigated object in this study. It was systematically investigated on the effect of addition level of lubricants and the addition methods of lubricants and strengthener on magnet density, density distribution and on magnet strength. By means of joint addition of lubricants and strengthener, which increases the magnet density and improves the magnet density distribution under the precondition of keeping the magnet strength unreduced. Thus the moldability of the bonded magnets is improved.     

The Effect of HDDR Process on Magnetic Properties in NdFeB Type of Bonded Magnets

The present paper describes the effect of alloy composition,homogenization anddehy-drogenization procedures on magnetic properties of NdFeB type of HDDR powders and the bondedmagnet.The results showed that the powders prepared by HDDR process possesses useful magnetic proper-ties and a better thermal stability than the sintered NdFeB magnet does.     

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.     

添加Zr对NdFeB合金HDDR磁粉的磁性能及显微组织的影响

本文主要研究了合金元素 Zr对 Nd Fe B合金 HDDR磁粉的磁各向异性和显微组织结构的影响。研究结果表明 ,Nd Fe Zr B合金磁粉出现了磁各向异性 ,且其显微组织中出现了针状的富 Zr相。     

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.