• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Plasma sprayed magnetic composites process, microstructure and properties.
【24h】

Plasma sprayed magnetic composites process, microstructure and properties.

机译：等离子喷涂磁性复合材料的工艺，显微组织和性能。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The dissertation presents research results from integrated studies of process, structure and magnetic properties of plasma-sprayed ferrite-metal composites. These magnetic composites are considered as the core materials for miniaturized high frequency planar inductors, thick film magnetoresistive sensors and potentially as magnetostrictive sensors. Offering the advantages of low substrate temperature during processing, high throughput production capability, cost efficiency and minimizing the interfacial reaction between the ferrite and metal phases, plasma spraying can be considered as a promising route for fabricating magnetic composites with industrial applications. A multitude of experimental techniques, including phase analysis, microstructure observation, magnetic property and electrical property measurements and numerical modeling have been applied for this investigation.;A number of fundamental attributes in terms of process-microstructure-property relationships have been investigated by a systematic processing approach through the frame work of process maps. Such studies can provide insight into process control and optimization.;Three types of magnetic composites have been fabricated using plasma spraying. Rocksalt structured monoxides form in the as-sprayed coatings due to deoxidation of ferrite as well as the oxidation of metallic particles. Random cation distribution and the presence of monoxides and microstructural defects, degrade the magnetic and electrical properties of the composites. Low temperature air annealing can improve these properties by means of forming insulating trivalent oxides (Hematite) and ordering the cations. Functional properties such as magnetoresistance and magnetostriction of comparable value to bulk materials can be obtained after annealing.;A salient finding is the transition form a giant magnetoresistance (GMR) to anisotropic magnetoresistance (AMR) at the percolation threshold which has been reported for the first time in magnetic composites. Thermally sprayed composites coatings are found to have a much smaller percolation threshold due to the anisotropy of splats. Using the effective medium approximation, the relationship between the percolation threshold and aspect ratio has been derived. The experimental results are in good agreement with simulation results. This is the first time that the percolation phenomenon in thermally sprayed composites has been studied quantitatively and compared with theory.
机译：本文通过对等离子喷涂铁氧体-金属复合材料的工艺，结构和磁性能的综合研究，提出了研究成果。这些磁性复合材料被认为是小型化高频平面电感器，厚膜磁阻传感器的核心材料，并有可能作为磁致伸缩传感器。由于等离子喷涂工艺的优点是加工过程中的基板温度低，生产能力高，成本效益高并且使铁氧体与金属相之间的界面反应最小化，因此可以认为是工业应用中制造磁性复合材料的有前途的途径。该研究采用了许多实验技术，包括相分析，显微组织观察，磁性能和电性能测量以及数值模型。;通过系统地研究了工艺-微观结构-性能关系方面的许多基本属性通过流程图的框架进行处理的方法。这样的研究可以提供对过程控制和优化的见识。；已经使用等离子喷涂制造了三种类型的磁性复合材料。由于铁素体的脱氧以及金属颗粒的氧化，在喷涂后的涂层中形成了岩盐结构的一氧化碳。随机的阳离子分布以及一氧化碳和微结构缺陷的存在会降低复合材料的磁性能和电性能。低温空气退火可以通过形成绝缘的三价氧化物（赤铁矿）和使阳离子有序来改善这些性能。退火后可以得到功能性特性，例如磁阻和磁致伸缩，其值可与块状材料相提并论。磁性复合材料中的时间。发现由于喷涂的各向异性，热喷涂复合材料涂层的渗透阈值要小得多。使用有效的介质近似，已得出渗滤阈值与纵横比之间的关系。实验结果与仿真结果吻合良好。这是首次对热喷涂复合材料的渗流现象进行了定量研究，并与理论进行了比较。

著录项

  • 作者

    Liang, Shanshan.;

  • 作者单位

    State University of New York at Stony Brook.;

  • 授予单位 State University of New York at Stony Brook.;
  • 学科 Materials science.;Electromagnetics.;Electrical engineering.
  • 学位 Ph.D.
  • 年度 2008
  • 页码 169 p.
  • 总页数 169
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号