Micro-precision surface finishing using magneto-rheological fluid

In order to improve the surface quality of machining workpiece,this paper studied a micro-precision surface finishing method by applying magneto-rheological fluid to the machined surface.A pin-on-disc testing apparatus was used to carry out surface finishing experiment of steel under different magnetic fields.Magneto-rheological fluid is colloidal suspension and stiffens in-to semi-solid when subjected to a magnetic field.Thus,the surface roughness of the finished surface could be controlled by magneto-rheological fluid under the different magnetic fields.Several sets of tests were performed with various normal loads,finishing speeds and magnetic fields.Removal rate was calculated by the removal loss monitored by testing apparatus,while microstructures of the finished surface of pin and disk were observed by scanning electron microscope.The micro-precision roughness of finished surface was analyzed by surface profilometer.The obtained test results showed different surface charac-teristics of the test material under different magnetic fields and proved the feasibility of this micro-precision surface finishing method to reduce the surface roughness of machining workpiece efficiently.At the same time,the effects of the various ap-plied normal loads and rotating speeds on the finishing surface by magneto-rheological fluid were investigated.