Properties of magneto-rheological fluids based on amorphous micro-particles
(1. School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, China;
2. School of Civil Engineering, Dalian University of Technology, Dalian 116024, China;
3. School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China;)
2. School of Civil Engineering, Dalian University of Technology, Dalian 116024, China;
3. School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China;)
Abstract: To improve the magneto-rheological (MR) properties of magneto-rheological fluids, self-made amorphous alloy particles, the composition of which was Fe76Cr2Mo2Sn2P10B2C2Si4, were used as the disperse phase to replace traditional carbonyl iron (CI) particles to prepare amorphous based magneto-rheological fluid (AMRF). Soft magnetic properties and densities of the amorphous particles and the CI particles were tested and compared. The results indicate the amorphous particles present a lower density but larger magnetization intensity and larger permeability at lower field levels. Properties of the AMRF with 20% particles in volume fraction were tested and compared with the CI based MR fluid (CMRF). The AMRF presents a saturation yield stress of 41 kPa at ~227 kA/m and a sedimentation ratio of 80%. The results indicate the magneto-rheological fluid based on amorphous micro-particles has better MR properties and sedimentation stability than that based on CI particles at lower field levels (0-200 kA/m).
Key words: magneto-rheological fluids; amorphous particles; carbonyl iron; soft magnetic properties; microstructure