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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。 相似文献
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利用高性能吸氢-歧化-脱氢-再复合(HDDR)NdFeB各向异性磁粉,通过两步法伴温磁场取向工艺制备高性能柔性各向异性NdFeB黏结磁体,重点研究了两步法伴温磁场取向工艺制备出不同成分配比磁体的磁性能和力学性能.结果发现:制备出磁体的取向度有大幅度提高,当成分配比(质量分数)为96.5%磁粉+1%偶联剂+2.5%黏结体系的磁体在120℃加热保温30 min磁场取向后,磁能积达到97 kJ·m-3,而磁体的矫顽力最大降幅只有1.3%,论证了两步法伴温磁场取向工艺制备柔性各向异性NdFeB黏结磁体在实际生产的可行性.环氧树脂润滑剂的加入使得制备出磁体的延伸率和柔性均大幅度下降,并且加入量越多,下降幅度越大,因此环氧树脂润滑剂最大加入量不应超过1%(质量分数). 相似文献
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为降低钕铁硼废料预处理成本,探讨利用盐酸润湿-空气自然氧化法对钕铁硼废料进行预处理,并对经盐酸润湿-空气自然氧化处理的钕铁硼废料中稀土的浸出工艺和浸出动力学进行研究.结果表明:以4 mol/L HCl润湿原料,在空气中放置20 d后铁的氧化率达到92.37 %,可满足铁硼废料中稀土回收的前期处理工艺要求,降低生产成本;在浸出的过程中,当反应温度为363 K,盐酸浓度为2 mol/L、粒度为0.055~0.088 mm、液固比VL/WS=8:1、搅拌速率500 r/min下,反应时间为60 min后经盐酸润湿-空气自然氧化Nd-Fe-B废料中稀土的浸出率可达89.36 %;研究表明,钕铁硼废料中稀土浸出过程主要是受扩散控制,其表观化学反应活化能E=17.49 kJ/mol. 相似文献
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Qisong Luo Yang Luo Zilong Wang Haijun Peng Wenlong Yan Wenjian Yan Tianhao Li Shengjie Zhu Dunbo Yu 《中国稀土学报(英文版)》2023,41(9):1353-1359
Anisotropic NdFeB/SmFeN hybrid bonded magnets were prepared by warm compaction process under an orientation magnetic field of 22 kOe,mixing with anisotropic SmFeN powders in different addition and HDDR-NdFeB powders in different coercivity.With the addition of 20 wt% SmFeN,the density and remanence of hybrid magnets increase from 5.58 g/cm3,8.4 kGs to 6.02 g/cm3,9.0 kGs,respectively.And as the addition amount of SmFeN powders varies from 20 wt% to 40 wt%,the maximum energy ... 相似文献
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注射成形钕铁硼粘结磁体研究的现状及前景 总被引:1,自引:0,他引:1
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。 相似文献
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在粘结NdFeB磁体模压成形过程中存在较大的压力损失,引起磁体密度分布不均匀,致使磁体密度减小。本文研究了压制压强、预压成形和压制方式等对粘结NdFeB磁体结构和磁性能的影响及机理。研究表明:随着压制压强提高,粘结NdFeB磁体的密度和磁性能显著增大;粒度配合、预压成形和双向压制等办法均可增大粘结NdFeB磁体的密度和磁性能;在适当的压制压强下,将粒度配合、预压成形及双向压制工艺结合,制备出密度达到6.5g/cm^3、磁能积达到104kJ/m^3的粘结NdFeB磁体。 相似文献
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Xiaowei Zhang Zilong Wang Tianhao Li Shengjie Zhu Dunbo Yu Wenlong Yan Yang Luo 《中国稀土学报(英文版)》2022,40(5):772-777
Based on the difference of the Y-terminal functional group of the silane coupling agent (Y–Si(X)3), four different silane coupling agents were employed to pretreat the surface of the NdFeB powders. The effects of silane coupling agents on the flowability and compressibility of compounds for preparing bonded NdFeB magnets were studied. It is indicated that compounds pretreated by silane coupling agents have weaker friction and meshing force. The apparent density is increased by 0.3 g/cm3 compared with the compound without silane coupling agent, and the radial crushing strength is significantly increased by about 3–4 times. In addition, the epoxy resin is more evenly distributed on the surface of the compounds treated by silane coupling agents observed by scanning electron microscopy, and some agglomerated particles are produced. Also, the compressibility of compounds with silane coupling agents is significantly improved due to the fact that hardening exponents are reduced. However, the addition of silane coupling agents has almost no effect on the magnetic properties of bonded magnets. The special energy was used to manifest the flowability of magnetic powder particles representing the macroscopic performance of the force between powder particles, providing a new direction for the study of the interface compatibility of two-phase or multiphase composite materials. 相似文献
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Pengjie Zhang Minggang Zhu Wei Li Guangqing Xu Xiulian Huang Xiaofei Yi Jingwu Chen Yucheng Wu 《中国稀土学报(英文版)》2018,36(5):544-551
The CeO2/epoxy resin composite coating was deposited on NdFeB substrate by cathode electrophoresis method for enhancing the anticorrosion and anti-wear performances. The morphologies and structures were characterized by a scanning electron microscope and an X-ray diffractometer. The micro hardness of the composite coating was evaluated by a microhardness tester. The corrosive behaviors of the coatings were studied by potentiodynamic polarization curve, electrochemical impedance spectroscopy and neutral salt spray tests. The concentration of CeO2 nanoparticles (NPs) in the electrophoresis bath was optimized according to the coating structures and anticorrosion performances. The results show that CeO2 NPs can enhance the microhardness of the composite coatings. Moreover, the nanoparticles disperse uniformly in the matrix when the concentration is lower than 30 g/L. The microhardness of CeO2/epoxy resin (30 g/L) composite coating is about 63% higher than that of the blank epoxy resin coating. And the NSS time of the CeO2/epoxy resin (30 g/L) composite coated sample can reach 1248 h. Meanwhile, the composite coatings possess no deteriorate influence on the magnetic properties of NdFeB substrates. The anticorrosion mechanisms of the composite coatings on the NdFeB substrate are deeply discussed. 相似文献
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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. 相似文献
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综述了粉末冶金温压工艺的研究进展,概述了温压工艺的粉末原料、聚合物、温度、压力、烧结环节对温压工艺的影响和温压工艺的致密化机理。详细介绍了温压工艺的新进展—流动温压、高压温压等,并对其应用前景进行了展望。 相似文献
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通过扫描电子显微镜观察和性能测试研究了硬脂酸锌、乙烯基双硬脂酰胺(ethylene bis stearamide,EBS)、复合润滑剂以及压制温度对Fe基粉末冶金材料温压工艺的影响规律。结果表明:当润滑剂加入量(质量分数)超过0.4%后,Fe基粉末的流动性和松装密度均随润滑剂加入量的增加而降低,其中加入单一EBS润滑剂的影响更大。添加润滑剂后增加了Fe基粉末冶金生坯的致密度,其中添加硬脂酸锌和复合润滑剂的Fe基粉末冶金生坯断口颗粒间结合更为紧密。润滑剂对提高Fe基粉末冶金试样生坯密度、烧结密度及抗弯强度的作用顺序为复合润滑剂硬脂酸锌EBS,Fe基粉末冶金材料的密度和力学性能均随温压温度的升高而增加。在最佳润滑剂加入量0.4%时,120℃温压Fe基粉末冶金试样密度比室温压制Fe基粉末冶金试样的密度提高了0.14~0.21 g/cm~3,硬度和抗弯强度提高了40%~65%。 相似文献
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为深入了解低成本法制备的C/C-SiC复合材料的摩擦磨损规律,以短炭纤维、Si粉、炭粉和粘结剂为原料,通过均匀混合、模压成形、1 600℃反应烧结制备了C/C-SiC复合材料,研究了孔隙度、SiC含量及环境湿度对该复合材料摩擦磨损性能的影响,并用光学显微镜及X射线衍射仪对磨屑进行观测分析,对不同状况下的摩擦磨损机理进行研究。结果表明:C/C-SiC复合材料的致密度决定其磨损方式;SiC在摩擦过程中作为硬质支撑点,其含量对摩擦系数及其稳定性具有关键性影响;湿态时的摩擦系数与线磨损均略有下降,但仍能保持其良好的摩擦磨损性能。 相似文献
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研究了温态流动成形复杂形状钨骨架的工艺.考察了钨骨架中Cu粉类型(雾化Cu粉,电解Cu粉,超细Cu粉)、粘结剂添加量和成形温度对钨骨架孔隙分布均匀性的影响.结果表明,添加35%体积分数的粘结剂并在压制过程中提高压制温度会明显改善钨骨架孔隙度分布的均匀性; 同时,由于不同Cu粉具有不同的表面形貌及粒度,对于钨骨架的孔隙度分布均匀性也有较大影响.由于超细Cu粉表面光滑、形状规则,添加了超细Cu粉和35%(体积分数)粘结剂的混合粉末在55℃时成形的钨骨架孔隙分布最均匀. 相似文献
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以组合雾化法制备的2024铝合金粉末和SiC颗粒为原材料,采用半固态粉末轧制法,在575~635℃温度下制备10%SiC_p/AA2024复合带材,研究粉末加热温度对带材显微组织与力学性能的影响,并与相同条件下制备的AA2024铝合金带材进行对比。结果表明:升高粉末加热温度可促进AA2024粉末变形或破碎,所得10%SiC_p/AA2024复合带材具有半固态特征的球状或近球状显微组织。与AA2024合金带材相比,SiC_p/AA2024复合带材的基体晶粒更加细小。SiC颗粒与液相Al没有发生显著的界面反应,未生成对体系有害的Al4C3物质。SiC_p/AA2024复合带材和AA2024合金带材的屈服强度、抗拉强度及伸长率都随粉末加热温度适当升高而提高,SiC_p/AA2024带材的屈服强度和抗拉强度分别在366~412 MPa和425~514 MPa之间,均明显高于AA2024合金带材,伸长率为3.1%~4.9%,断裂方式主要为脆性断裂。AA2024带材的屈服强度在265~348 MPa范围内,抗拉强度为362~423 MPa,拉伸断裂方式随加热温度升高由脆性断裂向韧性断裂转变。 相似文献