Experimental Study On Acoustic Emission Monitoring Of The Precision Grinding Process Of Optical Glasses

Optical glasses are widely used as optical components in the telescope,microscope,camera,sighting device and so on. With the demand of many more super-precision optical-elements on civil and national defense optical-system,optical elements'high efficiency processing technology has became a hotspots in the optics manufacturers at the basic of the elements'quality should be guaranteed.During the process of optical glasses to be precision grinded by diamond wheel, sudden and unexpected process disturbances would influence the stability of grinding state, consist of wheel wear and significant damage to the workpiece. And to efficiency monitor the grinding procedure is an important subject in the grinding domain. This issue focused on the monitoring of the grinding procedure of three optical glasses BK7, fused silica and fused quartz by means of acoustic emission, by analysis the AE signal in the time domain and the frequency domain we can study the law of AE signal by changes of the grinding parameters and the grinding state. As a result of these work, the wheel can be truing in time , the quality of the processed glasses'surface can be assured and the grinding efficiency also be improved. To sum up, this issue carry on some specific researches as following areas:Getted the basic capacity parameters of the BK7,fused silica and fused quartz as hardness, fracture toughness and the critical cut through the micro-indentation test. By the surface crack after indentation test of the three kinds of optical glasses, we carry on preliminary study of their processing performance.To carry on single-grit diamond grinding experiment on optical glasses monitored by AE and force-sensor, analysis the mechanism of the material removal of optical glasses during the grinding process, and the result also shows these two sensors have different mechanisms to monitor the scoring procedure. At the same time, we study the diamond's abrasion before and after the experiment, and analysis the mechanisms of the diamond's wear and tear during the scoring procedure.Establish the relationship between the AE root mean square(AErms) with the grinding depth, the velocity of the platform and the rotation speed of the wheel. At the basic analysis of the AE signals before and after the wheel truing on the time domain and frequency domain, this issue carry on the wavelet analysis of the AE signal, and get the energy coefficient of different frequency ranges of the AE signal. The result shows that AE signal is closely related to the grinding parameters and the wear of wheel, we can monitor and control the grinding procedure through the changes of the AE signal.