【摘要】 为研究不同种类磁性液体及密封工况对密封效果的影响，以Fe₃O₄为磁性颗粒，以链状氟醚油为基液，制备一系列不同颗粒含量、基液分子量的磁性液体，对磁性颗粒及磁性液体的结构、性能进行表征，在搭建的密封试验台上测试磁性液体种类及运行工况对密封耐压效果的影响。结果表明：制备的磁性颗粒粒径为纳米级，呈近球形形貌，具有较高的饱和磁化强度，磁性液体具有较好的分散稳定性；随颗粒含量增加、基液分子量增大，密封耐压值先增大后减小；在颗粒质量分数为30%、基液分子量为4 600 g/mol时，密封耐压值最高；随主轴转速增大，密封耐压值逐渐减小；随密封时间延长，密封耐压值先减小后趋于稳定。更多还原

【Abstract】 For research the effect of ferrofluids types and sealing conditions on the sealing effective, Fe₃O₄ used as magnetic particles, the chain PFPE-oil used as base liquid, and a series of ferrofluids with different particle concentrations and different molecular weights of base liquid were prepared, and the effects of the type of ferrofluids and operating conditions on the sealing pressure resistance were obtained.The structures and performances of magnetic particles and ferrofluids were characterized.The ferrofluids types and sealing conditions were test on the built sealing test bench.The results show that the prepared magnetic particles have nanometer size, near-spherical morphology, high saturation magnetization, and the ferrofluid has good dispersion stability.With the increase of particle content and molecular weight of base liquid, the sealing pressure increases first and then decreases.When the mass fraction of particles is 30% and the molecular weight of the base liquid is 4 600 g/mol, the withstand value of sealing pressure is the highest.With the increase of spindle speed, the sealing pressure value decreases gradually.With the extension of sealing time, the sealing pressure value decreases first and then becomes stable gradually.更多还原