Research On Laser-assisted Fast Tool Servo Machining Technology Of Glass-ceramics

Glass-ceramics has the advantages of extremely low coefficient of thermal expansion,high chemical stability,high strength,high hardness,low dielectric loss,and excellent biocompatibility.So it is widely used in various advanced and sophisticated areas.However,it has hard and brittle characteristics and its application surface is mostly a free-form surface.Therefore,it is low efficiency,high cost and poor quality in machining.To solve the above problems,the laser-assisted fast tool servo machining technology is proposed in this paper.This technology uses laser heating to improve the machinability of glass-ceramics while using fast tool servo technology to remove the material to create a free-form surface.The advantages of laser-assisted processing mainly lie in the ability to make hard and brittle materials warm up to "soften",change its difficult to machine;The advantages of fast tool servo machining technology to create free-form surfaces mainly lie in simple device structure,mature technology and easy control.This paper expects to verify the feasibility and superiority of creating freeform surfaces from glass-ceramics by using this technology through relevant simulation and experimental studies.Specific work is as follows:Complete the design and construction of the laser-assisted fast tool servo cutting device.The performance parameters of laser are introduced and the focusing lens is designed.The piezoelectric ceramic actuator selected in this paper and the common flexure hinge mechanism are introduced.On this basis,the flexure hinge mechanism used in this paper is designed,and the stiffness and maximum Angle are calculated.At the same time,simulation analysis is carried out to calculate the displacement output capacity and maximum stress of the flexure hinge.Combined with the lathe to complete the construction of the whole cutting system,to provide conditions for the subsequent experimental verification.The temperature field of laser-heated glass-ceramics was studied.Combined with the basic theory of heat transfer,the expressions of heat conduction differential equations in different coordinate systems are derived,and the common boundary conditions are given.According to the interaction mechanism between laser and glassceramics,the melting critical point of materials was analyzed.The simulation of the temperature field verifies the correctness of laser heat source loading and the temperature distribution of the material surface.The actual temperature measurement experiment of laser-activated glass-ceramics was carried out.On this basis,the subsequent processing experiment was arranged.Basic experimental research on laser-assisted fast tool servo machining of glass ceramics was carried out.The principle of cutting motion is analyzed and a diverging sine wave surface can be obtained when the cutting path of piezoelectric ceramics is driven by a sine wave signal.Several cutting experiments were carried out to find the relationship between different machining parameters,roughness,and roughness reduction.Finally,by comparing the wear condition of the tool,it is proved that the wear of the tool is slowed down obviously under the laser aid.