SGER: Exploration of Innovative Synthesis Routes for Meso-Scale Soft Magnetic Particulates

9900381 PULE这一小型探索性研究基金(SGER)探索了合成铁和铁钴合金中尺度颗粒(直径1000-2000 nm)的创新方法。目前还没有这种尺寸范围的颗粒，可用于制造更高强度、更稳定的磁流变液。研究了两种技术来制造这种大小范围的金属颗粒。第一种是以硫酸铁和氯化钴为前体还原金属盐的技术。合成是在氩气气氛下进行的，以限制表面氧化。外加磁场控制颗粒形状，乙醇和水的混合物控制颗粒大小。吸附水分的去除和结晶度的提高来自额外的处理。达到这一粒度范围的第二种途径是电火花侵蚀，必须确定这一过程是否能生产出合理数量的粉末。加州大学圣地亚哥分校的伯科维茨教授协助研究火花侵蚀方法。用包括洛伦兹显微镜在内的透射电子显微镜对颗粒进行了表征。磁流变液的样品将从粉末中制备并在流变仪中进行表征。%这是SGER，一个高风险项目，旨在创建中尺度的铁颗粒和铁钴颗粒。这些颗粒被认为是用于新型、稳定的磁流变液的理想材料。

9900381Phule This Small Grant for Exploratory Research (SGER) explores innovative routes for the synthesis of mesoscale particles (1000 - 2000 nm in diameter) of iron and iron-cobalt alloys. Particles in this size range are not presently available and are of interest for making higher strength, more stable magnetorheological fluids. Two techniques are examined to create metal particles in this size range. The first is a technique based on reduction of metal salts using iron sulfate and cobalt chlorides as precursors. Synthesis is conducted under an argon atmosphere to limit surface oxidation. An applied magnetic field controls particle shape and a mixture of ethanol and water controls the particle size. Adsorbed water removal and improved crystallinity results from additional processing. A second route to this particle size range employs spark erosion, and it must be determined if this process can make reasonable quantities of the powders. Prof. Berkowitz at UC-San Diego assists in the spark erosion approach. The particles are characterized by transmission electron microscopy including Lorentz microscopy. Samples of the MR fluids will be prepared from the powders and characterized in a rheometer.%%%This is SGER a high-risk project aimed at creating mesoscale-sized particles of iron and iron-cobalt particles. These particles are considered to be ideal for employment in novel, stable magnetorheologial fluids.***