Traditionally, the rheological properties of magnetorheological (MR) fluids are investigated under uniaxial steady (DC) fields. These basic fields promote the aggregation of magnetically attractive particles into chain-like structures aligned in the field driven direction. In this manuscript we show how triaxial unsteady fields can generate a variety of exotic mesostructures and influence the rheological response of the MR fluids. We bridge understanding the rheological response to each unique particle structure through videomicroscopy, x-ray microtomography and rheometry tests. Small-amplitude oscillatory shear and steady shear tests lay out an unmistakable argument for MR enhancement with both elevated storage modulus and yield stress responses following a sequence of steady uniaxial and unsteady fields. We demonstrate that structures assembled through time-averaged particle interactions or typical dipole–dipole magnetostatic interactions, especially when columnar structures are strengthened through lateral chain coalescence, can boost rheological response.

传统上，在单轴稳态（DC）场下研究磁流变（MR）流体的流变特性。这些基本场促进了磁性吸引力的粒子聚集成沿场驱动方向排列的链状结构。在本手稿中，我们展示了三轴非恒定场如何产生各种奇异的介观结构并影响MR流体的流变响应。我们通过视频显微镜，X射线显微断层照相术和流变学测试，了解对每个独特颗粒结构的流变响应。小振幅振荡剪切和稳态剪切测试为遵循一系列稳定的单轴和非稳态磁场而提高了储能模量和屈服应力响应的MR增强提出了明确的论据。