Research On Processing Technology Of Fused Quartz Material With Atmospheric Plasma

Optical quartz with ultra-precision surface and without damage layer is increasingly required for national major scientific project. However, the optical surface is produced still by the classical machining method like grinding or lapping. These machining methods generate very deep damage on the surface, because plastic deformation and brittle fracture of the material were utilized as a machining phenomenon. Chemical polishing methods can fabricate non-damage surface. Atmospheric pressure plasma polishing is a method using chemical reaction between active radicals excited by plasma and workpiece surface atoms, which can't damage the optical surface.At present, in order to meet project requirements for optical fused quartz materials, Center for Precision Engineer of HIT is developing related research work. Establish processing technology system, realize the stability of the processing, control linear relationship between removal speed and time and get ideal shape. The original system is designed for silicon wafer machining and fused quartz is quite difference with silicon in chemical nature, besides the shape of the discharge torch was not suitable for profile correction, consequently some improvement should be made. Through the modification of design scheme of plant, ultimately we determined the new torch, it improves the processing speed and meets processing accuracy while surface deposition relieves a lot.This paper also analysis the atmospheric plasma by the physical and chemical properties of the system. Theoretically introduce atmospheric plasma processing mechanism and characteristics. Verify the stability of system related properties by the short time repeatability, small disturbance and the linear time, and make experiments about the process parameters.With a large number of basis experiments, choose the proper technical parameters according to specific experimental test and plan experiments. Finally sort data, and build function equation between removal function model and three technological parameters in order to guide practical processing. Experimental results of verified test show that the expression can accurately predict processing effects.