各向同性粘结NdFeB磁体的温压成型工艺研究

采用温压成型的方法制备各向同性粘结NdFeB磁体,主要研究了成型温度、成型压力对磁体密度、磁性能及力学性能的影响。结果表明,采用温压成型工艺,可以在较低的压力下压制出高致密度的粘结NdFeB磁体。磁体磁性能随压制力的增加呈现先升高后降低的变化规律;温度越高,磁性能达到极值所需的压力越小。经过工艺参数优化后所制备的粘结NdFeB磁体获得了较高的磁性能与力学性能,其磁能积、抗压强度分别为88kJ/m3与192MPa。     

制备粘结钕铁硼磁体的温压工艺研究

将温压成型工艺应用于粘结钕铁硼磁体的制备过程,可以提高粘结磁体密度和磁性能.通过对室温压制工艺和温压工艺制得的粘结磁体对比,考察了压制压力与粘结磁体密度以及磁体磁性能之间的关系;考察了三种适用于温压工艺的粘结剂对磁体性能的影响,获得了制备粘结磁体的合理工艺参数,并以此为指导在温压温度为130℃条件下,获得密度为6.25kg/m^3、最大磁能积（BH）max为81kJ/m^3的粘结磁体.     

粘结剂和添加剂对注射成型各向异性粘结NdFeB磁体的影响(英文)

研究了在取向磁场下由HDDR磁粉注射成型的各向异性粘结NdFeB磁体,分析了粘结剂和添加剂对各向异性粘结NdFeB磁体的密度、磁性能以及抗压强度的影响.通过磁粉表面改性,磁粉的抗氧化性能以及磁体的磁性能都得到提高.比较了6种粘结剂对磁体性能的影响,从中得到比较理想的粘结剂,并且考察了抗氧剂以及润滑剂加入量对于磁体性能的影响.试验中,混炼温度为205～215 ℃,注射温度为265℃,注射压力为5～6 MPa,保压时间为5 s,模具加热温度为80℃.制得的磁体的性能为:Br=0.72 T,iHc=983 kA/m,(BH)max=75 kJ/m3.     

温压钕铁硼粘结磁体制备技术的研究

采用温压工艺制备了钕铁硼粘结磁体,研究了温压压力、温压温度、粘结剂种类及含量对磁体磁性能的影响,以及温压工艺对钕铁硼粘结磁体氧含量的影响.利用Nd2Fe14B/a-Fe系双相纳米晶磁粉为原料,在200℃下,采用12MPa的压力,获得性能最佳的磁体,其密度为6.43 g/cm3,磁性能为:Br=0.808 T,Hcb=461 kA/m,Hci=623 kA/m,(BH)max=101 kJ/m3.     

粘结剂含量对粘结NdFeB磁体力学性能和磁性能的影响

粘结剂作为粘结NdFeB磁体制备过程中的重要组成部分,其作用是提高磁粉颗粒的流动性和粘结强度,保证产品的力学性能和磁性能的稳定。采用理论与实验相结合的方法,研究了粘结剂含量对粘结NdFeB磁体力学性能和磁性能的影响。在此基础上,制备了高性能粘结NdFeB磁体。利用扫描电子显微镜（SEM）对磁体的结构和形貌进行了表征。在NIM-200C磁滞回线仪和电子万能试验机（AG-X plus）上分别测定了环形粘结NdFeB磁体（RSM）的磁性能和力学性能。结果表明,当粘结剂含量为3%（质量分数）时,粘结NdFeB磁体密度最高（5.59 g/cm³）,抗压强度最高（159 MPa）,磁性能最佳。     

粘结钕铁硼磁体阴极电泳工艺研究

粘结NdFeB磁体极易被腐蚀,因而需要涂层保护.本文研究了粘结NdFeB磁体的阴极电泳工艺,主要是电泳电压,电泳时间,电泳时漆液温度以及涂层烘烤固化对涂层抗蚀性的影响.研究发现用合适的工艺参数所获得的涂层能够显著提高粘结NdFeB磁体的抗蚀性能.     

NdFeB粘结磁体的使用温度及磁性能

对磁粉进行表面处理,利用冷、热模压法制备了金属基及塑料基两种粘结NdFeB磁体,研究了表面处理前后及不同基体磁体的使用温度和磁性能.研究结果表明磁粉的表面处理可以提高磁体的磁性能及使用温度,塑料基磁体的磁性能低于金属基磁体的,但其使用温度却较高,可达180 ℃左右.     

回收NdFeB磁体废弃物的HDDR法

<正>Alexadru Lixandru等人系统研究HDDR法的氢压力、氢解吸速度及温度对回收材料磁性影响,选择了6种NdFeB废料。通过研究确定了各种磁体完全岐化所需最佳氢压力。研究结果发现780℃和840℃两步氢处理和适当解吸速度,适用于Dy和Co含量较高的磁体,以便得到橡胶粘结磁体所需的各向异性HD-DR粉末。研究结果表明,电机中NdFeB磁体回收率较低,但扬声器中的NdFeB磁体回收率几乎高达100%。     

磁粉粒度分布和抗氧化剂对注射成型NdFeB粘结磁体性能的影响

本文研究了磁粉的粒度分布以及不同抗氧化剂的加入对注射成型NdFeB粘结磁体密度和磁性能的影响。结果表明，磁粉的粒度分布影响熔体的粘度，适当的粒度分布可以提高磁粉的松装密度和磁体的密度，获得高性能的粘结磁体；抗氧化剂的加入，很好地解决了NdFeB粘结磁体在湿热环境下易氧化生锈的问题，大大提高了磁体的抗氧化性能。     

固化条件对粘结复合磁体磁性能和抗压强度的影响

采用流动温压成型方法制备各向同性粘结NdFeB/锶铁氧体复合磁体,并研究了不同固化条件对磁体磁性能及抗压强度的影响。结果表明,直接在电阻炉中固化的磁体抗压强度最好,在氩气保护的环境下固化有助于提高磁体磁性能,当磁体在氩气保护的环境下于180℃时固化120min时获得了最佳的性能:剩磁Br=0.52T,内禀矫顽力Hcj=740.48kA/m,最大磁能积(BH)max=39.82kJ/m3,抗压强度σbc=185.98MPa。     

Research of warm compaction technology on nylon bonded Nd-Fe-B magnets

Warm compaction and room temperature compaction were applied to prepare bonded Nd-Fe-B magnets. The results indicated that the density of magnet was determined by the compaction pressure and warm compaction temperature, whereas, the thermosetting temperature could hardly affect the density of magnet. The mechanical properties of magnets were the best when the thermosetting temperature was 200 ℃. The Br, Hcb, and (BH)max of warm compaction magnet were higher than those of room compaction. When the warm compa...     

Magnetic properties and thermal stability of anisotropic bonded Nd-Fe-B magnets by warm compaction

Anisotropic bonded magnets were prepared by warm compaction using anisotropic Nd-Fe-B powder. The forming process, magnetic properties, and temperature stability were studied. The results indicate that the optimal temperature of the process, which was decided by the viscosity of the binders, was 110℃. With increasing pressure, the density of the magnets increased. When the pressure was above 700 MPa, the powder particles were destroyed and the magnetic properties decreased. The magnetic properties of the anisotropic bonded magnets were as follows: remanence Br = 0.98 T, intrinsic coercivity iHc=1361 kA/m, and maximum energy product BHmax = 166 kJ/m3. The magnets had excellent thermal stability because of the high coercivity and good squareness of demagnetization curves. The flux density of the magnets was 35% higher than that of isotropic bonded Nd-Fe-B magnets at 120℃ for 1000 h. The flux density of the bonded magnets showed little change with regard to temperature.     

Effect of bonding process on the properties of isotropic epoxy resin-bonded Nd-Fe-B magnets

Bonded NdFeB magnets were prepared by compression molding. The effect of preparation technology on their magnetic and mechanical properties was studied through the analysis of density, Br Hcj, (BH)max, bending strength, and compressive strength of the bonded magnets. The results showed that the magnetic properties decreased with increasing binder content, whereas the mechanical properties increased. Brand (BH)max increased with rising pressure, whereas Hcj decreased. For a fixed mass fraction of the binder, the optimal pressure was 620 MPa and the best thermosetting temperature was 160℃. These conditions made the bonded magnets have the optimal mechanical properties. Scanning electron microscopy (SEM) analyses of the fracture surfaces indicated that the epoxy resin bonded magnets exhibited brittle behavior.     

注射成型粘结NdFeB磁体的研发进展

简述注射成型粘结NdFeB磁体的制备工艺，分析了磁粉、粘结剂、取向磁场和工艺参数对注射成型粘结NdFeB磁体磁性能的影响以及该磁体的性能状况，并概述了粘结NdFeB磁体的产业发展及其应用领域，最后提出注射成型粘结NdFeB磁体的开发重点。     

High-temperature magnetic properties of anisotropic MnBi/NdFeB hybrid bonded magnets

Anisotropic Mn Bi/Nd Fe B(Mn Bi contents of0 wt%, 20 wt%, 40 wt%, 60 wt%, 80 wt%, and 100 wt%)hybrid bonded magnets were prepared by molding compression using Mn Bi powders and commercial hydrogenation disproportionation desorption and recombination(HDDR) Nd Fe B powders. Magnetic measurements at room temperature show that with Mn Bi content increasing, the magnetic properties of the Mn Bi/Nd Fe B hybrid bonded magnets all decrease gradually, while the density of the hybrid magnets improves almost linearly. In a temperature range of 293–398 K, the coercivity temperature coefficient of the hybrid magnets improves gradually from-0.59 %áK~(-1)for the pure Nd Fe B bonded magnet to-0.32 %áK~(-1)for the hybrid bonded magnet with 80 wt%Mn Bi, and the pure Mn Bi bonded magnet exhibits a positive coercivity temperature coefficient of 0.61 %áK~(-1).     

NdFeB粘结磁体材料研究新进展

综述了NdFeB粘结磁体粉末材料制备技术研究的主要进展.介绍了NdFeB粘结磁粉的主要制备方法及其工艺特点,讨论了不同制备工艺以及添加微量合金元素对NdFeB合金磁粉材料微观组织结构和磁性能的影响.在此基础上,指出了进一步提高NdFeB粘结磁体材料磁性能的可能途径及今后研究工作的方向.     

Nb含量对NdFeB合金HDDR工艺及显微组织的影响

探讨了Ｎｄ含量对纯三元ＮｄＦｅＢ合金氢化／歧化／脱氢／重组（ＨＤＤＲ）工艺以及其显微组织变化的影响。结果表明：Ｎｄ含量的增加促进了ＨＤＤＲ工艺过程加快、最佳工艺处理温度降低,并使其显微组织中晶粒尺寸的不均匀性增大。