摘要：为了研究磁性颗粒包覆厚度对磁流变液性能的影响,通过改变水溶液中聚乙烯醇的浓度来获取不同包覆厚度的磁性颗粒,以此配制磁流变液;对包覆颗粒的表面形貌、粒径及静磁性能进行表征,并测试不同包覆厚度的磁性颗粒制备的磁流变液的零场黏度、剪切屈服应力和沉降稳定性性能。结果表明:颗粒包覆厚度对磁流变液的零场黏度影响不大,对剪切屈服应力影响作用由弱到强再减弱;包覆层厚度增大,大颗粒团聚物更易形成,导致磁流变液沉降稳定性降低。

关键词：磁流变液；颗粒包覆；零场黏度；剪切屈服应力

Abstract： To research the influence of coating layer thickness of particles on property of magnetorheological fluid （MRF）， the magnetic particles with different thickness of coating layer were prepared by changing the concentration of PVA in solution and different types of MRF were prepared. The particle morphology， size and magnetic property were characterized， and the viscosity， shear yield stress and stability of different types of MRF were tested. The results show that different thickness of coating layer on surface of particles has less effect on viscosity without magnetic field， but leads the shear yield stress change from weak to strong and then weak again with the increase of magnetic field. The stability of MRF becomes worse due to the existence of big agglomerated particles when the thickness of particle coating layer gets thick. 

Keywords: magnetorheological fluid； particle coating； viscosity without magnetic field； shear yield stress； stability property