The Study Of The New MRF Liquid Containing Micro/Nano Magnetic Powder

Magnetorheological Finishing technology as the new ultra-precision finishing technology is very important for brittle optical element,especially for aspheric optical elements.MRF is composed of the base carrier liquid,magnetic particles,polishing powder and stabilizers by certain proportion,which is relatively high in processing efficiency.But it has the poor stability and is easy to particle agglomeration and settling phenomenon. In order to improve the polishing efficiency and the drawbacks of MRF fluid,adding nanoFe3O4 powder to MRF fluids formulates a new MRF fluids containing micro / nano powder.Finally explores its properties through a series of experiments.Details are as follows:1) Determines the preparation and composition of the new MRF fluid through a series of experiments.In the new MRF fluids,the base carrier liquid is deionized water,abrasive grains is CeO2, surfactants are sodium dodecyl sulfate and oleic acid,magnetic particles are carbonyl iron powder and nanoFe3O4.2) Study the stability of MRF fluid by detecting the fluid viscosity and sedimentation rate of MRF.With the content of carbonyl iron decreasing and nanoFe3O4 magnetic content increasing in the MRF fluid,the viscosity of the liquid increases and anti-settling capacity is enhanced.But with the size of Fe3O4 particle increasing,the viscosity of the liquid decreases and the anti-settlement capacity is weakened.3) verifies the performance of the new MRF polishing liquid through a series of experiments of polishing two kinds of quartz glass.Detecting the surface roughness and material removal is used to explore the MRF fluid polishing performance. With the content of carbonyl iron decreasing and nanoFe3O4 content increasing in the MRF fluid,the surface roughness value is decreased and the amount of material removed is increased.But when nanoFe3O4 is too much, the surface roughness value is increased and the amount of material removed is decreased.with the size of Fe3O4 particle increasing,the surface roughness value and the amount of material removed are decreased.The experiment results show that adding nanoFe3O4 powder can significantly improve the performance of MRF fluid. When the content of 20nmFe3O4 is about 15%in the new MRF liquid, performance of the new MRF is the best.After 45 min polishing experiment, surface roughness value of A quartz glass is reduced to 0.018μm from0.184μm and material removal of A quartz glass is 1μm,surface roughness value of B quartz glass is reduced to 0.583μm from 1.362μm.