Research On Grinding Process Of Hard And Brittle Materials Based On Laser Heat Assist

Hard and brittle materials,ceramics and glass are becoming more and more widely used in engineering.But its own nature determines the difficulty of its processing.Traditional machining methods are easy to produce cracks and microcracks on the machined workpiece,which limits the widespread use of hard and brittle materials.In this thesis,the grinding properties of quartz glass and high temperature alumina ceramics were studied under the condition of laser assisted heat treatment.The application of quartz glass in optical instruments is indispensable.In order to improve the processing efficiency and processing quality of quartz glass,a laser assisted thermal plastic grinding of quartz glass is proposed in this paper.The laser grinding of quartz glass is carried out by using resin bonded CBN grinding wheel.The hardness of silica glass is reduced and the ductility of quartz glass is improved by the heating of the laser,and the glass grinding of quartz glass is realized.The effects of laser power,P,feed rate,Vw,grinding depth,Ap and grinding wheel speed VS on the surface roughness,subsurface damage depth and residual stress of quartz glass were investigated.The experimental results demonstrate that the laser heat assisted grinding quartz glass has the best effect,the surface roughness is the smallest,and the microcrack depth of the quartz glass is reduced effectively when the laser power is about 200W.When the feed rate is increased and the grinding speed is decreased,the surface roughness decreases.When the laser power reaches 300W and above,the surface integrity of the quartz glass is damaged and cracks and cracks are generated.With high hardness,excellent wear resistance,low density characteristics,high temperature alumina ceramic engineering applications in the proportion of growing.The ratio of laser power(P)to feed rate(the applied spindle frequency HZ)should be lower than 0.3 when laser-assisted grinding of alumina ceramic by laser thermal assisted grinding.The laser heat assisted grinding of the laser power(the laboratory laser)should be lower than 100W,or will be heated alumina ceramic parts will produce melting,oxidation,rupture and so on.The surface roughness of the laserheat assisted grinding is significantly lower than that of the non-laser-assisted grinding,and the grinding removal rate in the laser-assisted area is significantly higher than that in the non-laser-heat-assisted grinding zone under the same processing conditions.