Experimental Investigation On Magnetic Abrasive Finishing For The Quartz Glass

Recently,with the development of science and technology,hard and brittle materials are widely used in various industries,especially in high-tech fields of communications,aerospace,optical instruments,etc.Hard and brittle materials with hardness and brittleness are low fracture toughness materials and difficultly processed by traditional finishing technology.The existing grinding and polishing methods for hard and brittle materials are difficult to process curved parts.In this paper,magnetic abrasive finishing with flexible and adaptable magnetic abrasive particles was used to process the inner surface of the quartz glass tube.The main research contents of this paper are as follows:(1)The magnetic field force,the force of the MAP on the workpiece surface and the force condition were analyzed in the machining.The removal model and brittle-ductile transition mechanism of hard and brittle materials were discussed,and the removal mechanism of magnetic abrasive finishing of hardand brittle materials was studied.The analysis showed that the removal mode of hard and brittle materials is composed of ductile mode,brittle-ductile mode(lateral cracks does not extend to the material surface)and brittle mode(lateral cracks has been extended to the surface)by magnetic abrasive finishing.(2)The unconsolidated magnetic abrasive of diamond were used for quartz glass plane finishing by MAF.The surface roughness of workpiece respectively achieves Ra 0.016?m and Rz 0.12?m.The feasibility of the processing of quartz glass by magnetic abrasive finishing was verified.The effects of spindle speed,machining gap,initial state and machining time on surface roughness were studied and analyzed.The optimal parameters were obtained.(3)According to the inner surface of the quartz glass tube,built-in magnetic pole is designed.The arrangement,number and groove size of combined pole are simulated by ANSYS Maxwell simulation software.Through analyzing the combined pole is assembled by ten tile-shaped poles of N45 Nd FeB.In each pole,the outer diameter is 35mm;inner diameter is 20mm;central angle is 36o;height is 40mm;groove width is 2mm.(4)The orthogonal experiment with four factors and three levels was designed to study important order of spindle speed,machining gap,mesh number of iron powder and abrasive particle size on influence of surface roughness of inner surface of the quartz glass tube.The optimal combination of factors and levels were obtained as follows: abrasive particle size 2.5?m,spindlespeed 960r/min,machining gap 1mm,mesh number of iron powder 200.And the scheme was verified by experiment.In this paper,through the theoretical analysis and experimental research,this paper verified the feasibility of precision machining of the inner surface of quartz glass tube by magnetic abrasive finishing,which has important significance for solving the problem of curved parts of hard and brittle materials.