| Fluid Magnetic Abrasive is a new type grinding of precision machining,,because of its special rheological properties,It has a broad development prospects for some modalities in finishing surface processing.But during the long-term process and storage,the reunion and precipitation of solid particles easily happened under the gravity and the interaction between particles,which because of the solid particles and fluid existing large density difference,it could not reach the requirements of processing required.To deal with this particular problem,which is directly restricting the production of this new type grinding tool,This paper makes research on the following aspects:1)According to the performance requirements and characteristics of Fluid Magnetic Abrasive,the various compositions of the liquid of magnetic abrasive is analyzed and selection,and the dispersion of solid particles in fluid is studied during the preparation.Based on this,the preparation technique of Fluid Magnetic Abrasive is improved.The influences of mixing technology,which combining mechanical agitation with pure rolling agitation,are studied on the stability of Fluid Magnetic Abrasive,and get a good preparation method,the stability of Fluid Magnetic Abrasive is improved.2)Based on the study of the dispersion mechanism of solid particles in liquid of Fluid Magnetic Abrasives,we put forward the method the influence of using compound surfactant on the the sedimentation rate and zero field.stability of Fluid Magnetic Abrasives,we select two groups compound surfactant reagents: polyacrylic acid(PAA)and sodium hexametapHospHate,sodium hexametapHospHate and sodium carboxymethyl cellulose.Through the extreme vertex design by Minitab software,the sedimentation rate and the liquid viscosity in zero field are as the goal,the two groups of surfactants and nano-silica are as ternary system,conducting experimental research,the best prediction formula ratio are obtained.The predicted results are verified through experiments.Both groups formula makes the stability and service life of Fluid Magnetic Abrasives has been greatly improved than the single surfactant.3)According to the theory of colloid and surface chemistry,combined with the experimental results,the dispersion mechanism of the above two groups of formula,and the dosage of both too little and too much of the mechanism is analyzed.4)The influence of the processing time and speed on the result of magnetic abrasive finishing is analyzed through experiment.Results show that both groups formula made by machining got very good surface roughness and the mirror effect.After processing the Fluid Magnetic Abrasives obtained good redispersibility. |
