磁性纤维随机混合媒质等效电磁参数的计算

为计及强散射偶极子间的相互作用,引入参量εh和μh,利用广义多重散射理论及MATLAB计算机软件对在2 GHz～18 GHz频率下的体积占空比为8%的铁纤维随机混合媒质等效磁导率的实验值进行曲线的拟合,导出了耦合系数εh和μh,并在此基础上,对体积占空比分别为30%和20%的铁纤维随机混合媒质等效磁导率进行了计算,计算结果与实验吻合良好.     

2000年—2001年磁性功能材料研究和应用新进展

综述了磁性功能材料研究和应用在2000年－2001年间的新进展，其内容包括：（1）自旋电子学；（2）Bi-Fe氧化物的磁性；（3）稀有和稀土金属垂直磁记录材料；（4）新的多层膜磁性材料；（5）磁浮列车。     

熔融织构YBCO块样品的磁特性研究

对MTG区熔生长法,慢冷法,粉末熔融生长法这3种方法制备的熔融织构YBCO块样品进行了交流磁化率和磁阻的测量。根据实验结果计算了样品的钉扎势,并且发现3种方法制备的样品在150 mT外磁场下均显示出基本消除弱连接的特性;粉末融熔生长法所制样品中有较纯净123相和较好织构,质量最好。     

Effect of sintering process on microstructure and magnetic properties of high frequency power ferrite

An oxide ceramic process was adopted to prepare high frequency manganese-zinc (MnZn) power ferrite. In combination with the microstructure analysis of material, the influences of sintering process on initial permeability (μi) and high frequency loss in unit volume (Pcv) of MnZn power ferrite were investigated. The results show that in order to obtain fine microstructure and high frequency properties, the preferable sintering temperature and atmosphere are 1230 ℃ and oxygen partial pressure ( PO2) of 4%, respectively.     

Study on sintering process and characteristic of nanosized soft magnetic MnZn ferrite powders

The effect of sintering process (especially the sintering temperature) on the magnetic property and microstructure of sintered sample of nanosized soft magnetic MnZn ferrite powder was investigated. The sintered sample of MnZn ferrite was prepared by both traditional pressing and cool isostatic pressing on MnZn ferrite nanoparticals. The sintering process of which was segmented. Thedensity, microstructure and phase composition of sintered sample were analyzed by Archimedes'law, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The grain growth and densification in sintering process of MnZn ferrite were investigated. The magnetic property was measured by vibrating sample magnetometer (VSM) and Nim2000 magnetic material testing system. The results show that the better sintering temperature is 850 ℃, at which the better magnetic property and microstructure of sintered compact were obtained.     

Microstructure and magnetic performance of Ni-substituted high density MnZn ferrite

The effects of NiO on microstructure and magnetic properties of Mn-Zn ferrite with a nominal composition of Zn0.32Mn0.60-xNixFe2.08O4 were investigated. The calcined powder of Mn-Zn ferrite was characterized by X-ray diffraction (XRD), the fracture surface of Mn-Zn ferrite was checked by scanning electronic microscope (SEM), and then the magnetic properties were measured. As a result, the substitution of Ni can cause the crystallattice constant of MnZn ferrite to decline, and the grain size to decrease, therefore improve the magnetic performance of MnZn ferrite whose density exceeds 5.0 g·cm-3.     

确定电磁超声换能器钢管检测最佳磁化强度的试验研究

由于电磁超声换能器检测钢管缺陷时,其磁场强度影响超声波幅值,进而影响检测灵敏度。为此设计了确定最佳磁化强度的试验方案,通过试验得到超声波幅值随电磁场激励电流的变化曲线。确定了最佳磁化强度时的激励电流。     

纳米晶Fe72.8Cu1Nb1.7V1.5Mn0.5Si13.5B9软磁合金的磁性能

本文报道了高导磁纳米晶Fe72．8Cu1Nb1．7V1．5Mn0．5Si13．5B9合金的直流和交流磁性能水平，磁导率频散行为以及高频铁损行为，给出了描述高频区频散行为和铁损行为的近似表达式。     

高速切削机床中的磁轴承

高效化是机械制造的永恒主题之一。本文简介了高速切削的理论依据及其优点，分析了磁悬浮轴承的原理、特点以及磁浮轴承在高速切削机床上的应用情况，从而说明了磁浮轴是高速切削机床最理想的轴承之一。     

各向异性Sm2Fe17Nx磁粉的结构与磁性能

研究了Sm2Fe12Nx磁粉的制备、结构与磁性能，发现Sm—Fe合金的铸态组织主要由Sm2Fe17、α—Fe和SmFe2三种物相组成，而经过1000℃均匀化退火48h处理后富Sm的SmFe2相基本消失，α—Fe相的品粒变小，数量减少。随着氯化时间延长到10h，Sm2Fe17相始终未改变其Th2Zn17型结构，而氯原子浓度增加，所有的X射线衍射峰均向小角度方向移动；但在氮化时间超过10h后，物相要发生变化，导致磁性能降低。在500℃下流动的氮气氛中对Sm2Fe17合金氮化2、4、6、10h未加磁场取向的磁粉中，以氮化6h的磁性能值最高：σr＝35．44Am^2/kg(emu／g)，Hc＝58kA／m(729．03Oe)。磁性能值偏低的原因与测量磁场较低，粒径分布不均匀及粒径较大有关。