Research On Arc Waviness Controlling Technology Of Diamond Cutting Tool Based On AE Monitoring

The development of ultra-precision machining technology has brought great convenience to our daily life.High-quality optical components and Nano-precision semiconductor products need ultra-precision processing technology in the manufacture of these products.High-precision diamond cutting tools has been playing an important role in ultra-precision technology.Among them,diamond cutting tools with arc edge are the most widely used.The arc waviness of diamond cutting tools has an important influence on the quality of machined surface.Nano-scale workpiece surface can not be machined without controlling the arc waviness of diamond tools.At present,the manufacturing technology of diamond cutting tools in China still lags behind that in developed countries.In order to improve the manufacturing technology of diamond tools in our country,the research on the control technology of arc waviness of diamond tools based on acoustic emission monitoring is carried out.Firstly,the acquisition system of AE signal during diamond grinding is established,and the analysis and processing technology of AE signals is studied.A method of AE signal denoising based on wavelet threshold method is proposed in this paper.In view of the shortcomings of soft threshold method and hard threshold method in signal denoising,an improved threshold method is proposed.The parameter analysis method and time-frequency analysis method are used for extracting the characteristic parameters after denoising.Secondly,the anisotropy of diamond is studied by diamond typical crystal surface grinding experiment,the grinding direction of diamond is changed during experiments to explore the variation law of acoustic emission signal,and the mapping relationship between acoustic emission signal characteristic parameters and diamond grinding direction is established.Grinding parameter experiments were carried out to study the variation of characteristic parameters of acoustic emission signals.Then,the influence of the motion structure of the grinding machine on the arc cutting of the tool is analyzed.The grinding process of the diamond tools is summarized and divided into three stages: rough grinding,semi-finishing and fine grinding.The value threshold method for the diamond tool grinding state identification was proposed,the diamond tool grinding process parameter experiments were carried out,and the influence of the spindle speed,the swing shaft speed,the grinding pressure and the reciprocating stroke on the arc waviness of the diamond tool was explored.Finally,according to the results of the grinding parameters experiments,the radial basis neural network model was trained.After the model iteratively converges,the parameters of the grinding process were optimized.The circular arc waviness of thediamond tool processed according to the optimized parameters was under 100 nm with100°.In order to further improve the arc waviness of diamond tools,an arc waviness control technology based on fixed angle dressing was proposed.The angle information of the diamond tool flank face corresponds to the time information of the acoustic emission signal.After analyzing the time domain of the acoustic emission signal,the area of the diamond tool was fixed to dress,after optimizing the arc profile of diamond tool,the PV value of the diamond tool profile reduced and arc waviness was promoted to 60 nm with 80°.