共查询到19条相似文献,搜索用时 156 毫秒
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《制造技术与机床》2015,(9)
以45钢和不锈钢SUS304为研究对象,研究采用磁力研磨法对磁性和非磁性工件的微小沟槽表面的光整加工。通过理论分析,解析磁力研磨的加工机理。分别采用径向充磁和轴向充磁圆盘环形永磁铁作为磁极,结合Ansys磁场模拟分析与磁力研磨实验,探讨不同材质工件微小沟槽表面的光整加工工艺。实验结果表明:对于45钢微小沟槽表面的光整加工,不能选用圆盘环形轴向充磁磁极,应该选用圆盘环形径向充磁磁极,研磨加工后沟槽底面的表面质量要好于侧面;对于不锈钢SUS304微小沟槽表面的光整加工,选用圆盘环形轴向充磁磁极更适合,加工后底面和侧面都能获得较好的表面质量,加工效率较高。 相似文献
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磁力研磨是利用磁性磨料和磁场作用进行研磨加工的一种研抛技术.讨论了不同研磨头形状对磁力研磨的影响以及研磨头设计的要点.在五自由度并联机床上利用不同形状磨头对自由曲面的模具进行了磁力研磨试验.开槽研磨头比不开槽研磨头的研磨效果要好得多.实验分析了利用球型磨头对工件磁力研磨时,磁场强度、研磨间隙、研磨时间等因素对自由曲面模具表面研磨质量的影响.利用五自由度并联机床不仅可以去除自由曲面模具表面的切削残留痕迹,降低模具的表面粗糙度,还可解决传统手工研磨方式所引起的工件研磨质量不一致的缺陷。 相似文献
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交流励磁三维定位系统中磁传感器设计 总被引:2,自引:0,他引:2
交流励磁定位系统可以对介入式微型医疗装置在人体内的三维位置实现非接触式遥测。在定位系统中,为了测量磁场分布范围宽、下限磁场微弱的交变磁场,本文设计开发了感应线圈式磁传感器。根据电磁感应原理,感应线圈先将交变的磁信号转换为电信号,再通过后级信号处理电路在强大的噪声背景中提取出有用的电信号,结合传感器的输入输出特性,即获得待测磁场大小。实验结果表明:磁传感器能准确测量微弱交变磁场,且具有宽测量范围、高分辨率、高稳定性和高精度的优点。磁传感器还能适用于一切非导磁环境中跨度大的交变磁场的测量,具有通用性。 相似文献
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During the past ten years magnetic force microscopy (MFM) has become probably the most powerful general-purpose method for magnetic imaging. MFM can be applied under various environmental conditions and requires only little sample preparation. Basic research on magnetic materials as well as the mentioned industrial applications create an increasing demand for high-resolution magnetic imaging methods. This contribution will review some new concepts which have been realized in the field of advanced probe preparation, based on electron beam methods in order to improve the spatial resolution beyond 100nm. It is shown that the advanced probes allow high-resolution imaging of magnetic fine structures within thin film permalloy elements exhibiting a complicated cooperative magnetization reversal process. These investigations are of importance for various concepts underlying modern magnetic data storage developments. Furthermore, we present some developments of MFM to suit the needs of the magnetic recording industry. 相似文献
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Sun LT Zhao HW Zhang ZM Wang H Ma BH Zhang XZ Li XX Feng YC Li JY Guo XH Shang Y Zhao HY 《The Review of scientific instruments》2007,78(5):053302
Two high magnetic field hexapoles for electron cyclotron resonance ion source (ECRIS) have successfully fabricated to provide sufficient radial magnetic confinement to the ECR plasma. The highest magnetic field at the inner pole tip of one of the magnets exceeds 1.5 T, with the inner diameter (i.d.)=74 mm. The other hexapole magnet provides more than 1.35 T magnetic field at the inner pole tip, and the i.d. is 84 mm. In this article, we discuss the necessity to have a good radial magnetic field confinement and the importance of a Halbach hexapole to a high performance ECRIS. The way to design a high magnetic field Halbach structure hexapole and one possible solution to the self-demagnetization problem are both discussed. Based on the above discussions, two high magnetic field hexapoles have been fabricated to be utilized on two high performance ECRISs in Lanzhou. The preliminary results obtained from the two ECR ion sources are given. 相似文献
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管道内外壁缺陷的有效区分是对缺陷进行有效量化的前提,提出一种基于动生涡流的高速漏磁检测过程中管道内外壁缺陷的定位区分方法,利用涡流磁场与外磁场的耦合作用时内外壁磁场信号的变化差异特征区分缺陷位置。首先建立高速漏磁检测数学模型,分析了涡流分布特点以及涡流磁场与外磁场耦合作用规律,利用有限元方法计算分析不同位置时,耦合作用规律对管道内外壁磁化状态影响及内外壁缺陷漏磁场信号差异特征;设计高速漏磁检测实验平台,对不同运行速度、不同检测位置处钢管内外壁缺陷区分效果进行实验研究。结果表明,接近磁化线圈位置时,管壁内产生的涡流磁场方向与管道外壁磁场方向相同、与管道内壁磁场方向相反,在离开磁化线圈位置时,涡流磁场方向与管道外壁磁场方向相反、与管道内壁磁场方向相同;不同检测位置处,管壁磁场变化规律相反,且速度越快,磁化状态影响受影响程度越大,内外壁漏磁场信号差异特征越明显,高速检测时可有效对管道内外壁缺陷进行定位区分,实验结果和理论分析具有很好的一致性。 相似文献
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为了提高磁致伸缩液位传感器的检测精度,研究了磁致伸缩液位传感器中产生偏置磁场的浮子磁铁的放置方式及其对检测电压的影响。利用ANSYS软件对浮子磁铁不同放置方式下形成的偏置磁场进行了有限元分析,分析显示:采用3块磁铁互成120°N极N极S极(NNS)放置或者采用圆环磁铁作为偏置磁场时检测效果比较理想。实验研究了磁致伸缩液位传感器的偏置磁场对检测电压的影响,并在浮子磁铁不同放置方式下进行多次实验。结果表明:偏置磁铁为3块磁铁互成120°NNS放置时或者为圆环磁铁时,检测电压的幅值达到50mV,比其它放置方式提高了近30mV。研究表明:磁致伸缩液位传感器应选择3块磁铁NNS放置或者选择圆环磁铁作为偏置磁场。 相似文献
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The effect of a magnetic field on the wear of ferromagnetic metals (nickel and iron) has been investigated. Wear tests were carried out under an external magnetic field applied horizontally or vertically to the rubbing surface in atmospheres of air, nitrogen and argon. In air a magnetic field horizontal to the surface enhances specific wear. However, a magnetic field vertical to the surface accelerates the severe-to-mild-wear transition, so that it gives a remarkable reduction in specific wear. In nitrogen or argon a vertical magnetic field does not have this effect. The reduction in specific wear is thought to be due to the chemisorption of oxygen onto the ferromagnetic metals activated by the application of a vertical magnetic field. 相似文献
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Barada KK Chattopadhyay PK Ghosh J Kumar S Saxena YC 《The Review of scientific instruments》2012,83(6):063501
Current free double layers (CFDLs) are localized potential structures having spatial dimensions - Debye lengths and potential drops of more than local electron temperature across them. CFDLs do not need a current for them to be sustained and hence they differ from the current driven double layers. Helicon antenna produced plasmas in an expanded chamber along with an expanding magnetic field have shown the existence of CFDL near the expansion region. A helicon plasma device has been designed, fabricated, and installed in the Institute for Plasma Research, India to study the role of maximum magnetic field gradient as well as its location with respect to the geometrical expansion region of the chamber in CFDL formation. The special feature of this machine consisting of two chambers of different radii is its capability of producing different magnetic field gradients near the physical boundary between the two chambers either by changing current in one particular coil in the direction opposite to that in other coils and/or by varying the position of this particular coil. Although, the machine is primarily designed for CFDL experiments, it is also capable of carrying out many basic plasma physics experiments such as wave propagation, wave coupling, and plasma instabilities in a varying magnetic field topology. In this paper, we will present the details of the machine construction, its specialties, and some preliminary results about the production and characterization of helicon plasma in this machine. 相似文献
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利用自行研制的磁性液体进行艺术字字模、展示台、磁铁升降系统、电动机传动装置、电气控制部分等的设计和加工,并且利用磁性液体场致界面不稳定性,研制出磁性液体艺术字展示装置。将该装置接通电源后,在磁场作用下4个艺术汉字将依次瞬间动态呈现。在呈现过程中,磁性液体逐渐突起的尖峰个数、高度、间距均与永磁场之间存在规律性的变化,这种变化规律将启示观察者进一步研究神奇液体材料的结构组成,为深入研究场致磁性液体界面不稳定性奠定基础。 相似文献