The Process Experimental Study On Magneto-rheological Finishing For Optical Glass

It is a trend of using small diameter aspherical lens in the modern optical system to improve the optical properties. The processing efficiency and processing precision of traditional polishing methods to small-diameter aspheric optical are difficult to meet industry requirements. the bottle necks of polishing technology to small-diameter aspherical lens and components is how to polishing the workpice with high efficiency and precision, so it is urgent to develop a new type of advanced polishing method with highly efficient and high-qualityMagneto-rheological Finishing Technology (MRF) is a new type of optical processing technology developed in recent years to obtain super-smooth surface without damage. Most conventional magnetorheological finishing used polishing wheel, it is difficult to polish samll size concave lens less than 10mm.This research is from the national 863 subject—development of ultra-precision aspherical machine tools.In order to solve the polishing problems in conventional magneto-rheological finishing, the researchs are carried out as following:(1)A new samll polishing pad is designed to polish samll concave. MRF polishing experimental apparatus including magnetic field generator, polishing head and fixture.(2)By analyzing the magneto-rheological fluid composition, properties, rheological mechanism and performance requirements, optimize the magneto-rheological polishing fluid composition and develop a qualified liquid for magneto-rheological finishing. The influences of various components on polishing are analyzed.(3)Using the magnetorheological finishing experimental apparatus and the developed magneto-rheological fluids,the influence of polishing tool's shapes on surface roughness is investigated in such factors as magnetic intensity, working gap, rotational speed of magnetic pole and polishing time. Optimize polishing parameters by orthogonal test analysis of different processing parameters on the extent of the effect of polishing. And then discuss the removal mechanism of glass and polished using metallographic photos of the results are analyzed.(4)The simulation of the magnetic field distribution has been carried out for polishing tools, the influence on surface morphology of magnetic field strength and speed is analyzed at the same time. Establish magnetic field strength and speed of the relationship with the mathematical model.