Fe-Ga波导丝的磁致伸缩位移传感器结构设计

为减小剩磁和驱动脉冲电流对磁致伸缩位移传感器检测信号的影响,进而提高传感器的测量精度,对FeGa磁致伸缩位移传感器的结构进行设计,提出了一种移动线圈式结构的磁致伸缩位移传感器,此时永磁体固定在波导丝头部,位置线圈在波导丝上移动起到位移改变的作用。制作了新结构的传感器样机,实验结果表明:与传统结构相比,结构改进后检测信号的信噪比由13.4 d B提高至25.2 d B,检测电压幅值由52 m V提高至80 m V,且能实现回波速度校正。移动线圈式磁致伸缩位移传感器能有效改善传感器的线性度、重复性和迟滞性。     

静态磁场谐振磁传感器设计

为了解决磁致伸缩/压电复合磁传感器测量静态磁场时需要交变激励磁场以及磁电电压输出低等问题,提出了一种改进结构的磁致伸缩/压电/音叉复合谐振磁传感器,采用COMSOL有限元仿真软件对传感器的应力与应变分布以及音叉的振动模态进行仿真.结果表明,传感器的谐振频率随着磁场强度的增加近似线性递增;在0～1 000 Oe磁场范围内,灵敏度达1. 750 5 Hz/Oe,是改进前的7倍,验证了传感器改进结构的有效性.     

R(Fe0.95Mn0.05)x合金的显微结构与磁致伸缩的研究(R=Dy0.6Tb0.3Pr0.1,1.7≤x≤2.0)

采用金相、X射线衍射、电子探针显微分析和标准应变测试技术研究了电弧浇铸的R(Fe0.95Mn0.05)x(R=Dy0.6Tb0.3Pr0.1,1.7≤x≤2.0)合金的显微结构与磁致伸缩.结果表明,合金的基体为MgCu2型立方结构的(Dy,Tb,Pr)(Fe,Mn)2相, 当x≤1.8时,第二相为富稀土相,当x>1.85时,变为(Dy,Tb,Pr)(Fe,Mn)3相.合金的磁致伸缩测量表明,当x≤1.80时,磁致伸缩随x的增加而增加,当x>1.85时,磁致伸缩随x的增加而降低.对于采用提拉技术制备的R(Fe0.95Mn0.05)x取向样品,当x=1.85时磁致伸缩呈现出一个峰值.相对于电弧浇铸的样品,取向样品的磁致伸缩特性得到改善.     

超磁致伸缩换能器磁路设计及优化

为优化超磁致伸缩换能器的电磁性能,研究了线圈的几何尺寸和磁路元件的选择对换能器磁场特性和输出位移的影响,并进行了磁路损耗和气隙磁导分析.给出了合理的线圈结构参数,提出了在超磁致伸缩材料(GMM)棒两端安装高磁导率的软磁体和减少GMM棒涡流损耗的设计方案,并忽略了气隙的影响.采用有限元方法仿真了不同磁路设计方案对换能器性能的影响,并进行了试验分析.结果表明,在GMM棒两端安装电工软铁能够提高工作磁场强度,减少磁通泄漏,增加换能器输出位移并降低驱动电流,改善换能器的发热情况,从而整体改善超磁致伸缩换能器的性能     

单片机在磁致伸缩线性位移传感器中的应用

以磁致伸缩原理为基础,利用单片计算机对位移量进行精确的测量,且可以通过按键校准磁致伸缩线性位移传感器的零位和满量程,并使用单片计算机标准串行口经TTL/485电平转换,输出所测量的位移量数据的方法,使得该类型磁致伸缩线性位移传感器操作简单、互换性好、有效传递测量的数字量数据达1 km以上.     

超磁致伸缩驱动器设计方法的研究

在分析超磁致伸缩材料(GMM)工作特性、超磁致伸缩驱动器(GMA)基本结构与工作原理的基础上,给出了机电磁设计参数的确定准则和数学模型,提出了超磁致伸缩驱动器的一般设计理论与方法.在该方法指导下设计实现的超磁致伸缩驱动器最大输出位移达36 μm,定位精度为0.1 μm,性能达到设计要求.试验结果验证了该方法的可操作性和有效性.     

磁致伸缩微定位平台的设计及特性分析

针对现有微定位平台输出位移小和输出力不足的问题,设计了一种磁致伸缩微定位平台。依据磁致伸缩微定位原理设计了微定位平台的结构,并创建了磁致伸缩微定位平台的动态位移输出模型,通过微定位平台的动态位移输出模型建立了微定位平台的数学模型并计算得出定位平台的位移量;利用有限元仿真软件建立了磁致伸缩微定位平台三维仿真模型,由仿真结果得出磁致伸缩微定位平台的仿真位移量;最后通过实验测量磁致伸缩微定位平台的位移,验证磁致伸缩微定位平台的工作性能。实验测得的结果和仿真计算的结果进行对比可知磁致伸缩微定位平台实际位移量为64μm,计算位移量为60μm,仿真位移量为67μm,三者对比分析,磁致伸缩微定位平台的测量误差较小,精度较高,有一定的应用研究价值。     

SDMSA双磁致伸缩线性位移传感器标定实验研究

为获得SDMSA型号的双磁环磁致伸缩线性位移传感器位置量与输出电压的特性关系,在自制的传感器标定的实验台上,对位移传感器测杆产生的激励磁场和双磁环产生的偏置磁场与双磁环间的间距的关系进行了研究,建立了双磁环磁致伸缩位移传感器的输出电压模型.在相同偏执磁场的作用下,探究双磁环间距与输出电压的关系,通过实验进行关系推导.得...     

稀土磁致伸缩材料Terfenol-D的变负载特性分析研究

关于稀土超磁载伸缩材料Terfeno1-D的磁致伸缩特性国内外已有大量报道，但大多数都是基于载荷(预紧力)在磁致伸缩过程中保持不变条件下的磁致伸缩特性研究．在这些研究的基础上分析了Terfenol-D材料在变负载时的磁致伸缩特性。介绍了变负载动态特性曲线的绘制方法并讨论了恒载与变载的特性曲线的特点与差异。对设计和研究磁致伸缩换能器的动态特性具有参考价值．     

超磁致伸缩材料Terfenol-D的磁致伸缩特性曲面拟合

介绍了超磁致伸缩材料的伸缩现象并针对试验中涉及到的稀土磁致伸缩材料的动态特性,采用乘积型最小二乘法拟合出二元曲面S(H,P)的函数式并计算出它的动态磁致伸缩量.为进一步设计磁致伸缩致动器提供初步的数据.     

Study on NiO/Fe interface with X-ray photoelectron spectroscopy

Different monolayers(ML)of Fe atoms were deposited on NiO(001)substrates or NiO underlayers using molecular beam epitaxy(MBE),pulse laser deposition(PLD),and magnetron sputtering(MS).The magnetic properties and microstructure of the films were studied The apparent magnetic dead layer(MDL)is found to exist at the NiO/Fe interfaces of the MBE sample(about 2 ML MDL),the PLD sample(about 3 ML MDL),and the MS sample(about 4 ML MDL).X-ray photoelectron spectroscopy indicates the presence of ionic Fe(Fe~2+ or Fe~3+ and metallic Ni at the NiO/Fe interfaces,which may be due to the chemical reactions between Fe and NiO layers.This also leads to the formation of MDL.The thickness of the MDL and the reaction products are related with the deposition energy of the atoms on the substrates.The interfacial reactions are effectively suppressed by inserting a thin Pt layer at the NiO/Fe interface.     

Microstructure and AMR Properties of Permalloy Films Sputtered on (Ni_ (0.81)Fe_(0.19)_ (0.66)Cr_(0.34 )Buffer

1　IntroductionTheanisotropicmagnetoresistanceeffect (AMR)waswidelystudiedinthepastyearsbecauseofitspracticalapplicationinmagneticandelectronicdevices ,eg ,themagneticsensorsandreadouthead[1 3 ] .Ni0 .81Fe0 .19hasex cellentmagneticsoftness ,andwasgenerall…     

Effect of annealing on the characteristics of Au/Ni50Fe50 bilayer films grown on glass

Sputter-deposited Au/Ni_(50)Fe_(50) bilayer films were annealed in a vacuum of 5×10~(-4) Pa at 523 to 723 K for 30 or 90 min. The characteristics of the bilayer films were determined by Auger electron spectroscopy, field emission scanning electron microscopy, X-ray diffractometry, a four-point probe technique, and an alternating gradient magnetometer. When the annealing temperature and time reached 723 K and 90 min, Ni and Fe atoms markedly diffused into the Au layer. The grain size of the Au layer did not change markedly with the annealing condition. As the annealing time was 30 min and the annealing temperature exceeded 573 K, the resistance of the bilayer film increased with increasing the annealing temperature. Furthermore, the resistance of the bilayer film annealed at 723 K for 90 min was lower than that of the bilayer film annealed at 723 K for 30 min. All the bilayer films showed magnetic hysteresis loops. The as-deposited bilayer film showed a hard magnetization. The bilayer film represented an easy magnetization with increasing the annealing temperature. The Au/Ni_(50)Fe_(50) film that annealed at 723 K for 90 min had the lowest saturation magnetization.     

Fe基软磁非晶态合金的研究

从合金的非晶形成能力和磁性能两个方面对多组元铁基非晶Fe Ni P B(TM M)系和Fe Co Ni Zr Nb B(TM (Zr,Nb) M)系的成分设计进行了分析 ,采用单辊铜轮快速急冷 (quenching)的方法制取非晶条带 ,X射线衍射及透射电镜 (TEM)分析均证明 :本研究制得试样为均匀的非晶合金 .此外 ,从非晶合金的磁滞回线上可知 ,所制得的Fe基非晶合金具有良好的磁性能 .     

Fabrication and characterization of highly ordered Ni0.5Zn0.5Fe2O4 nanowire/tube arrays by sol-gel template method

Highly ordered nanowire/tube arrays of Ni0.5Zn0.5Fe2O4 were fabricated by the sol-gel method in the pores of anodic alu- mina membrane (AAM). Whether nanowires or nanotubes were fabricated depends on immersion time. The immersion time was 15-40 s for nanotubes and over 60 s for nanowires. The topography and crystalline structure of the nanowire arrays were character- ized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). It was found that the length and diameter of the Ni0.5Zn0.5Fe2O4 nanowires are related to the thickness of the AAM and the diameter of the pores. The results indicated that the Ni0.5Zn0.5Fe2O4 nanowires are uniform and parallel to each other.     

烧结机头除尘灰理化性能及磁性特征分析

以某烧结厂烧结机头除尘灰为研究对象,采用SEM、XRD和化学分析等对其进行理化性能分析,并通过磁选实验对其磁性特征进行了研究。结果表明,烧结机头除尘灰的理化性能随其所在电场不同而产生变化,除尘灰中Pb、Zn、Cu重金属与K、Na碱金属含量明显高于成品烧结矿,除尘灰中Fe主要以Fe2O3形态存在,Pb主要以PbCl2和Pb2 O2 Cl形态存在,K和Ca分别以KCl和CaCl2形态存在,干法磁选实现了除尘灰中部分铁元素回收。     

稀土超磁致伸缩微致动器设计与实验

作为微制造平台主动隔振系统微致动器核心部件,超磁致伸缩微致动器的工作性能将直接影响整个系统的控制精度.选择Terfenol-D作为微致动器主要材料,设计了一种新型超磁致伸缩微致动器.电磁结构设计中,采用电磁场解析计算进行初步设计,进而采用有限元法对致动器的结构和线圈参数进行进一步的分析与优化.静态特性实验结果表明,该微致动器具有较大的静态位移输出、力输出及较小的位移滞回.     

Effect of annealing time on the exchange coupling interactions and microstructure of nanocomposite Pr7.5Dy1Fe71Co15Nb1B4.5 ribbons

The influence of annealing time on the magnetic properties and microstructure of nanocomposite Pr7.5Dy1Fe71Co15Nb1B4.5 ribbons was systematically investigated by the methods of vibrating sample magnetometer (VSM), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Interaction domains derived from strong exchange coupling interactions between hard and soft magnetic grains were imaged using magnetic force microscopy (MFM). Maximum remanence, intrinsic coercivity, and maximum energy product values were obtained in the ribbons annealed at 700℃ for 15 min, which were composed of Pr2(Fe, Co)14B, α-(Fe, Co), and slight Pr2(Fe, Co)17 phases. Although Jr, Hci, and (BH)max decreased gradually with further increase of annealing time, it is emphasized that comparatively high Jr and Hci and (BH)max were obtained in a wide annealing time period of 15 to 360 min. The shape of initial magnetization curves and hysteresis loops change as a function of annealing time, indicating different magnetization reversal routes, which can be fully explained by the corresponding microstructure.     

离子掺杂和碳修饰对Li_2FeSiO_4结构和性能的影响

采用高温固相反应方法合成锂离子电池正极Li_2Fe_(1-x-y)Mn_xNi_ySiO_4/C复合材料,并采用X-ray线衍射、扫描电子显微镜和电化学分析方法,研究了Ni和Mn离子共掺杂及碳修饰复合改性对复合材料结构和性能的影响。结果表明,复合改性没有对材料的晶体结构造成改变,镍锰离子共掺杂和表面碳包覆能有效提高材料的比容量和循环性能;以C/32倍率充放电,复合掺杂得到的Li_2Fe_(0.6)Mn_(0.2)Ni_(0.2)SiO_4/C材料样品的电化学性能最优,根据实测结果,该复合材料的首次放电比容量达到149 m Ah·g~(-1),充放电循环10次以后容量保持率仍有95.3%。     

磁场调谐的啁啾光纤光栅延迟线

利用Tb0.3Dy0.7Fe1.95的磁致伸缩特性调谐线性啁啾光纤光栅延迟线,将中心反射波长1550nm,啁啾系数2.58nm/cm,长度60mm,3dB带宽15.48nm的线性啁啾光纤光栅两端牢固地粘在长度为70mm、直径为8mm的磁致伸缩棒上,并置于一个均匀线圈磁场中,当线圈电流从0A增加到2A时,粘在磁致伸缩棒上的线性啁啾光纤光栅受到轴向应变,反射谱向长波长方向平移了1.6nm,实现最大60ps的时延调谐量,这种装置可以使阵元间隔为0.006m的四阵元光控相控阵雷达系统工作在25GHz时,实现0°～90°的扫描。