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

9900381探索性研究小额资助（SGER）旨在探索合成铁和铁钴合金中尺度颗粒（直径1000 - 2000 nm）的创新途径。该尺寸范围内的颗粒目前不可用，并且对于制备更高强度、更稳定的磁流变流体是有意义的。 研究了两种技术以产生在此尺寸范围内的金属颗粒。 第一种是基于使用硫酸铁和氯化钴作为前体还原金属盐的技术。 在氩气气氛下进行合成以限制表面氧化。 外加磁场控制颗粒形状，乙醇和水的混合物控制颗粒大小。吸附水的去除和结晶度的改善来自于额外的处理。 达到该粒度范围的第二种途径是采用电火花腐蚀，并且必须确定该方法是否可以制造合理数量的粉末。 加州大学圣地亚哥分校的Berkowitz教授协助研究电火花腐蚀方法。 通过包括洛伦兹显微镜的透射电子显微镜表征颗粒。 将从粉末中制备MR流体样品，并在流变仪中进行表征。% SGER是一个高风险项目，旨在制造铁和铁钴颗粒的中尺度颗粒。 这些颗粒被认为是理想的就业在新的，稳定的磁流变液。

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.***