Rheological properties of magnetorheological fluids
Rheological properties of magnetorheological fluids
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DOI：
10.1088/0964-1726/11/1/316
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发表时间：
2002-02-01
影响因子：
4.1
通讯作者：
Phulé, PP
中科院分区：
文献类型：
--
作者：
Genç, S;Phulé, PP
研究了分散相饱和磁化强度和外加磁场对磁流变液流变性能的影响。制备了基于具有不同平均粒度的两种不同等级羰基铁粉的MR流体，7-9 μ m（等级A）和2 μ m（等级B）。振动样品磁强计测量结果表明，饱和磁化强度值分别为2.03和1.89 T的A级和B，分别。用特制的双库埃特应变速率控制流变仪在0.2 T至0.8 T的磁通密度范围内对33和40 vol%的A级和B级磁流变液进行了流变学测量。在0.8 +/- 0.1 T下，33和40 vol%A级的屈服应力分别为100 +/- 3和124 +/- 3 kPa。基于较细颗粒（B级）的MR流体的屈服应力值始终较小。例如，在0.8 +/- 0.1 T下，33和40体积%等级B基MR流体的屈服应力分别为80 +/- 8和102 +/- 2 kPa。在接近磁饱和的磁通密度下（B与0.8T相似），屈服应力随分散磁相的饱和磁化强度μ（0）M（s）呈二次方增加。这与Ginder及其同事开发的均匀饱和粒子链的分析模型非常一致。本文给出的结果表明，基于更细颗粒的MR流体的屈服应力的降低是由于更细颗粒的相对较小的磁化。
The effects of dispersed phase saturation magnetization and applied magnetic fields on the theological properties of magnetorheological (MR) fluids are described. MR fluids based on two different grades of carbonyl iron powder with different average particle size, 7-9 mum (grade A) and 2 mum (grade B), were prepared. Vibrating sample magnetometer measurements showed that the saturation magnetization values were 2.03 and 1.89 T for grades A and B, respectively. Rheological measurements were conducted for 33 and 40 vol% grade A and grade B based MR fluids with a specially built double Couette strain rate controlled rheometer at flux densities ranging from 0.2 to similar to0.8 T. The yield stresses of 33 and 40 vol% grade A were 100 +/- 3 and 124 +/- 3 kPa, respectively at 0.8 +/- 0.1 T. The yield stress values of MR fluids based on finer particles (grade B) were consistently smaller. For example, the yield stresses for 33 and 40 vol% grade B based MR fluid were 80 +/- 8 and 102 +/- 2 kPa, respectively at 0.8 +/- 0.1 T. The yield stresses at the flux density approaching magnetic saturation in particles (B similar to 0.8T) were found to increase quadratically with the saturation magnetization (mu(0)M(s)) of the dispersed magnetic phase. This is in good agreement with the analytical models of uniformly saturated particle chains developed by Ginder and co-workers. The results presented here show that the decrease in yield stress for finer particle based MR fluids is due to the relatively smaller magnetization of the finer particles.