Sedimentation stability is one of the most important features of magnetorheological (MR) fluids. Clay-based additives are known for improving the stability of the MR fluids. This article describes the dependency of the clay-based additive concentration on the sedimentation stability and the rheological properties of MR fluids in non activated state (without magnetic field). The sedimentation was measured for two different base oil viscosities, two different carbonyl iron particle sizes, and additive concentration between 2 and 6 wt%. The measurements showed that the sedimentation rate exponentially decreases with the additive concentration, while the yield stress is rising. The measurements of rheological properties also showed the dependency of rheological properties of MR fluid with a clay-based additive on loading history. The influence of carrier fluid viscosity or particle size has a minor effect on the sedimentation in comparison with the clay-based additive. The addition of 6 wt% slows down the sedimentation by more than 3000 times compared to MR fluid without additives. The MR fluid with 4.85% of clay-based additive achieves slightly better sedimentation stability than commercial MR fluid LORD MRF122.

沉积稳定性是磁流变（MR）流体的最重要特征之一。已知基于粘土的添加剂可改善MR流体的稳定性。本文介绍了粘土基添加剂浓度对非活化状态（无磁场）下MR流体的沉降稳定性和流变特性的依赖性。针对两种不同的基础油粘度，两种不同的羰基铁粒度以及2至6 wt％的添加剂浓度测量了沉降。测量结果表明，沉降速率随添加剂浓度的增加而呈指数下降，而屈服应力则呈上升趋势。流变性质的测量还显示了具有粘土基添加剂的MR流体的流变性质对加载历史的依赖性。与粘土基添加剂相比，载液粘度或粒径的影响对沉降的影响较小。与不含添加剂的MR流体相比，添加6 wt％可使沉淀速度降低3000倍以上。具有4.85％粘土基添加剂的MR流体比商业MR流体LORD MRF122具有更好的沉降稳定性。