廉价(40％MM-Nd-Pr)_(16)-Fe-B_(6.8)永磁材料的研究

本文研究了添加元素及各种工艺因素对基本成分为(40％MM-Nd-Pr)_(16)-Fe-B_(6.8)合金磁性能的影响。其最高性能为:Br=1.12T(11.2kG),iHc=636kA/m(8.0kOe),(BH)_(max)=227kJ/m~3(28.5MGOe)。还初步分析了合金的相结构,测定了合金的居里温度(Tc)。     

廉价稀土铁5Ce-MR-Fe-B永磁合金研究

本文叙述以5％Ce代替MR-Fe-B中富Nd的混合稀土(MR)所制成的廉价高性能永磁体的研究。研究了合金成分及工艺因素对5Ce-MR-Fe-B磁性能的影响。确定了最佳成分及其工艺制度。可以稳定生产的该类永磁体的磁性能为B_r=1.10～1.18T(11.0～11.8kG);_iH_c=560～800kA/m(7.0～10.0kOe);(BH)_(max)=240～256kJ/m~3(30～32MGOe)。这种永磁合金开路磁通可逆温度系数为-0.11％/℃,居里温度305℃,维氏硬度HV>520。     

添加润滑剂对烧结钕铁硼磁体性能的影响

研究了烧结钕铁硼永磁材料的粉末流动性及添加润滑剂对粉末流动性与磁体取向度和磁性能的影响.结果表明:影响松装状态磁粉流动性的主要因素是粉末颗粒团聚,影响密实磁粉流动性的主要因素是颗粒间的摩擦力.添加适量的润滑剂可以防止粉末颗粒团聚、明显地减小摩擦力,改善粉末流动性,提高磁体的取向度、剩磁与磁能积.采用添加润滑剂和橡皮模等静压制成型工艺,批量生产的烧结钕铁硼磁体性能达到:Br=1.457 T,jHc=1148 kA/m(14.43 kOe),(BH)max=408 kJ/m3(51.3 MGOe).     

歧化氢压对Nd12.5Fe80.4-xCoxGa0.5Zr0.1B6.5各向异性HDDR磁粉性能的影响

主要研究了d-HDDR工艺及添加合金元素Co对Nd12.5Fe80.4-xCoxGa0.5Zr0.1B6.5(x=0、4、8、12、15)合金磁性能的影响规律.结果表明,氢压是HDDR磁粉吸氢歧化产生磁各向异性的重要敏感因素,0.025MPa的歧化氢压对提高磁粉的各向异性具有最好的效果,磁能积达到:Br=1.252T,jHc=768.7kA/m,(BH)max=253.4kJ/m3,DOA=0.58.(合金元素Co的添加有益于HDDR磁粉磁性能改善,在0～15%(原子分数),随着Co含量增加d-HDDR磁粉的磁能积逐渐增大.     

Nd—Fe—B粘结磁体磁粉制备

本文所介绍的Nd-Fe-B粘结磁体磁粉的制备系采用铸态Nd-Fe-B合金高温氢气爆裂法。氢爆过程由氢化—加温—真空脱氢等步骤组成。加热温度为750～950℃。本方法制备的粘结磁体的内禀矫顽力H_(ci)≥800kA/m;各向同性的最大磁能积(BH)_(max)≥32kJ/m~3。     

HDDR技术制备高性能稀土永磁磁粉研究

利用HDDR技术研究了NdFeCoBZrGa合金的磁性能.研究了HD处理温度对合金磁粉磁性能和DOA的影响规律;研究了DR处理温度对合金磁粉磁性能和DOA的影响规律;研究了合金成分对合金磁粉磁性能和DOA的影响规律.结果表明通过适当工艺的调整,成功制备出高性能、高各向异性粘结磁体磁粉.对于成分为Nd13FgbalCo17B6 5Zr01Ga10的合金,其磁性能达到iHc=817.6kA/m,Br=1.18T,(BH)max=244kJ/m3,其取向度DOA达到0.56.     

Structural and Magnetic Properties of Mechanically Alloyed Nd_(15)Fe_(70)T_(15)N_δ(T=V, Mo) Magnets

Structural and magnetic properties of Nd15Fe70T15Nδ(T=V, Mo) alloys, made by mechanical alloying (MA) followed by heat-treatment and nitriding, have been investigated systematically.Effects of annealing temperature on the structure and magnetic properties of the materials were studied by means of X-ray diffraction, AC susceptibility and high field magnetization measurements. Under pure argon atmosphere, the optimum temperatures for the heat treatment are found to be 75 and 850℃ for Nd15Fe7015Nδ and Nd15Fe70Mo15Nδ respectively. Correspondingly, the following magnetic properties are achieved : (1) Nd15Fe70V15Nδ:Br=0.63 T,,HC=8.01kA/cm (10.1 kOe), (BH )max=50.3 kJ/m3 (6 32 MGOe), (2) Nd15Fe70Mo15Nδ :Br=0.42 T. iHc=5.6 kA/cm (7.4 kOe), (BH )max=26.6 kJ/m3 (3.34 MGOe)     

Nd13Fe80.1-xTixB6.5Zr0.1Cu0.3永磁合金磁性能研究

HDDR(氢化-歧化-脱氢-再结合)工艺是制备各向异性Nd2Fe14B基磁粉的有效方法.主要研究了改进的d-HDDR工艺及添加合金元素Ti对Nd13Fe80.1-xTixB6.5Zr0.1Cu0.3(x=0、1.0、2.0)合金磁性能的影响规律.结果表明,d-HDDR工艺中吸氢氢压和歧化时间是促使材料产生磁各向异性的#合金经d-HDDR工艺处理,其最佳磁性能为:Br=1.39T;iHc=1006kA/m;(BH)max=169.66kJ/m3;DOA=0.797.关键;合金元素Ti使NdFeB合金矫顽力显著提高,其作用主要体现在两方面:一方面是在晶界间形成低熔物,抑制晶粒长大、细化晶粒,改善富Nd相的组织结构,使富Nd相沿边界更加均匀地分布;另外,Ti元素使Nd2Fe14B晶界平直而清晰,主相晶粒表面各向异性提高,反磁化畴难以形核,从而使矫顽力提高,其最佳添加量为1.0%(原子分数).成分为Nd13Fe79.1Ti1.0B6.5Zr0.1Cu0.3 的2#合金经d-HDDR工艺处理,其最佳磁性能为:"Br=1.39T;iHc=1006kA/m;(BH)max=169.66kJ/m3;DOA=0.797.     

各向异性Nd_(12.5)Fe_(68.9-x)Co_(12)Ga_xZr_(0.1)B_(6.5)磁粉研究

采用d-HDDR(室温吸氢后"氢化—歧化—脱氢—再复合")工艺制备Nd12.5Fe68.9-xCo12GaxZr0.1B6.5(x=0,0.1,0.3,0.5,0.7)永磁磁粉,研究了歧化氢压、脱氢再复合温度、脱氢再复合真空度及合金元素Ga对Nd12.5Fe68.9-xCo12GaxZr0.1B6.5合金磁性能的影响规律,利用X射线衍射仪(XRD)对磁粉的相结构进行表征。结果表明,d-HDDR工艺中,合金的相变过程为:Nd2(Fe,Co)14B+2H22NdH2+12α-(Fe,Co)+(Fe,Co)2B;0.03MPa的歧化氢压是NdFeB磁粉产生磁各向异性的关键,脱氢再复合阶段采用高温,低真空与高真空相结合的制度是NdFeB磁粉获得高各向异性的保证;添加Ga元素有益于提高磁粉的矫顽力和各向异性,其最佳添加量为0.3%(原子分数),Nd12.5Fe68.6Co12Ga0.3Zr0.1B6.5磁粉的典型性能为:(BH)max=218.3kJ/m3,Br=1.22T,jHc=751.2kA/m,DOA=0.52。     

HDDR各向异性NdFeB及其各向异性形成机理研究

各向异性粘结NdFeB是目前稀土永磁研究的一个热点。本工作研究了NdFeB-M合金(M=Co、Ga、Zr)在吸氢-歧化-脱氢-复合过程(hydrogenation-disproportionation-desorption-recombination,简称HDDR)中各向异性形成的机理和HDDR各向异性NdFeB磁粉及粘结磁体制备技术。 首次发现合金元素M在歧化过程中富集在NdH_2/α-(Fe,Co)相界,形成Nd_2(Fe,M)_(14)B微结构,成为与母相Nd_2(Fe,M)_(14)B晶体位向一致的“记忆点”。在合适的再复合热力学和动力学条件下,仅发生‘记忆点’形核并具有足够高的形核率,最终得到具有晶体织构的细小晶粒组织,结果形成各向异性和实现磁硬化。 通过对HDDR工艺的实验研究,发现在从“氢化-歧化”阶段进入“脱氢-再复合”阶段的中间温度和氢压调整阶段对各向异性形成具有决定性影响。在此基础上提出了适合稳定制备HDDR各向异性NdFeB磁粉的“多阶段再复合工艺”,其典型磁粉的性能为Br=1.22T,Hci=930kA/m,BHm=248kJ/m~3。 研究了HDDR各向异性粘结NdFeB磁体的成型技术。发现静磁场温压成型、脉冲室温成型都适合制备HDDR各向异性粘结NdFeB磁体。所得粘结磁体的磁性能为Br=0.88T,Hci=930kA/m,BHm=128kJ/m~3。还设计和制造了适合于批量生产的全自动脉冲取向成型装置以及各向异性粘结磁体的注塑成     

含Ti和C的纳米复合Nd2Fe14B／α—Fe磁体研究

研究Ti和C添加对Nd9.4Fe79.6B11合金磁性能的影响规律。结果表明:Ti和C联合添加能够在不降低合金剩磁的情况下显著提高合金的矫顽力,最佳工艺条件下制备出的Nd9.4Fe75.6Ti4B10.5C0.5合金薄带的剩磁Br=0.91T,矫顽力Hcj=975.6kA/m,磁能积(BH)max=135.4kJ/m3。在磁体密度为6.1g/cm3时,黏结Nd9.4Fe75.6Ti4B10.5C0.5磁体剩磁Br=0.68T,内禀矫顽力Hcj=975kA/m,最大磁能积(BH)max=76 kJ/m3,性能和MQ-D磁粉制备的黏结磁体性能相当,具有低价位高性能的特点。     

纳米晶复合Nd9.5Fe81-xCoxZr3B6.5永磁材料磁性能的研究

采用熔体快淬及晶化退火工艺制备了Nd9.5Fe81-xCoxZr3B6.5(x=0、2、5、8、10)纳米晶合金条带,研究了Co的添加对快淬合金磁性能和居里温度的影响.结果表明,适量Co元素的添加能够有效降低各相晶粒的尺寸,增强了软、硬磁相晶粒的交换耦合作用,从而提高了合金的磁性能.Co含量为5%(原子分数)的合金,经670℃/4min的晶化处理后所得到的最佳磁性能为`Br=0.90T,jHc=588kA/m,(BH)max=117kJ/m3.     

粘结剂对注射成型钕铁硼粘结磁体性能的影响

为了制备出高性价比的注射成型粘结钕铁硼永磁材料,系统地研究了粘结剂对注射成型磁体的加工性能、磁性能和力学性能等的影响。用国产的快淬钕铁硼磁粉和尼龙6粘结剂制备出了磁性能为Br:0．5158T,Hcb：321kA／m,Hcj：730kA／m,(BH)m：40kJ／m^3的注射钕铁硼磁体。     

Au-Fe-Ni permanent magnet alloys

A gold permanent magnet for an ornamental material is developed in the Au-Fe-Ni system. It is found that the magnetic properties of the An-12.5 wt% Fe-12.5 wt% Ni alloy aged at 450°C for seven hours and cold-swaged by 92 percent are Br = 0.53 T (5300 G), iHc = 40.8 kA/m (510 Oe), and (BH)max = 9.1 kJ/m³(1.1 MGOe). The Au-12.5 wt% Fe-10 wt% Ni-2.5 wt% Co alloy aged at 450°C for 2.5 h and swaged by 86 percent attained Br = 0.54 T (5400 G), iHc = 42.4 kA/m (530 Oe), and (BH)max = 9.6 kJ/m3(1.2 MGOe). In these alloys, the magnetic hardening is due to the fine Fe-Ni rich ferromagnetic particles precipitated in the Au matrix.     

Magnetic Properties and Structure of Nanocrystalline Nd4.5Fe76Co1B18.5 Alloys

In this paper, the technology, structures and magnetic properties of Nd4.5Fe76Co1B18.5 nanocomposite magnets were investigated. The effect of crystallizing treatment temperature and time on structures and magnetic properties of Nd4.5Fe76Co1B18.5 amorphous ribbons was studied. The results show that Nd4.5Fe76Co1B18.5 containing more analogue metals is easy to form a morphous. The magnetic properties of 16 m/s quenched ribbon for 710 degrees Cx900 s crystallizing treatment reach H-i(c)=242.1 kA/m, B-r=0.9410 T and (BH)(max)=59.64 kJ/m(3). The even grain size is about D-Fe3B=34 nm and D-Nd2Fe14B=23 nm.     

Magnetic Properties and Thermal Stability of Pr_(1-x)La_xCo_(5-y)Alloys

Pr1-xLaxCo5-y (x=0, 0.15. 0.25, 0.35,1.0, y=0.5, 0.7, 0.9, 1.0) alloys were investigated. The effect of the variation of x and y on magnetic properties and thermal stability of the alloys were studied. The magnetic properties for the Pr0.85La0.15Co4.3 and Pr0.75La0.25Co4.1 magnets are iHc=368 kA/m, Br=0.91 T, (BH)max=145.6 kJ/m3, αBr=-0.03%/℃ and iHc=568 kA/m,Br=0.8 T, (BH)max=127.2 kJ/m3,αBr,=-0.06%/℃, respectively The phase structures of as-cast alloys and magnets were investigated     

Structural and Magnetic Properties of Sm_3(Fe,Ti)_(29) and Sm_3(Fe,Ti)_(29)X_y (X=H, N) Compounds

1. IntroductionRecelltly new intermetallic compounds NdZ(Fe,Ti)lo and RZ(Feo.91Vo.og)19 (R=Y, Nd, Sin, Gd) werediscovered by Collocott et al.II] and Shcherbakovaat al.IZ], respectively. The crystal structure of thesenew phases has been identified to be Nd3(Fe, Ti)29type structure using X-ray diffraction by Li et al.I3].Among them, the Sin3(Fe,Ti)29N. compound exhibitsstrong uniaxial anisotropy' and its saturation magnetization is very close to that of S.,Fe,,N;'] compound.The hydr…     

粘结剂对粘结钕铁硼/锶铁氧体复合磁体磁性能的影响

为获得磁性能适中的磁体,采用流动温压成型技术制备了各向同性粘结Nd Fe B/锶铁氧体复合磁体.利用振动样品磁强计(VSM)研究了不同粘结剂对粘结Nd Fe B/锶铁氧体复合磁体磁性能的影响.研究表明:环氧值适中的酚醛环氧树脂制备的磁体具有较好的磁性能;当采用环氧值为0.480 mol/100 g酚醛环氧树脂BPANE8200H做粘结剂时,粘结Nd Fe B/锶铁氧体复合磁体获得了最佳的磁性能:Br=0.55 T,Hcj=620.6 k A/m,(BH)max=45.6 k J/m3.在保证磁体磁性能的前提下兼顾力学性能,粘结磁体流动温压成型温度参数的设置必须考虑粘结剂的软化点温度.