Research On Ultrasonic Vibration Milling Of BK7 Optical Glass Surface Morphology

With the rapid development of technology and the urgent needs of manufacturing industry, Optical glass materials were widely used in many modern high-tech industries, such as aerospace, electronics and information. In general, lenses, prisms, mirrors and windows were made by optical glass in optical instrument or mechanical system. But as the typical hard brittle material, optical glass had many unique features, for example greater hardness, higher strength and larger fragility. On the traditional cutting, surface cracks and dimples would appear on the machined surface, In order to obtain high-quality and high-precision work-pieces machined surface, usually the process was accomplished by rough grinding-fine grinding- polishing, however this machining model not only had a long period of time and high processing costs, but also the machining accuracy could not be guaranteed.When made a research on the characteristics of BK7 optical glass materials, found that under certain conditions optical glass could improve surface accuracy by plastic domain processing. Based on kinematic analysis of ultrasound, vibration theory, the formula of maximum residual height’s formula of surface and the calculation method of elastic-plastic deformation, finally had built the theoretical model of the surface roughness on ultrasonic vibration milling.In this paper a reasonable ultrasonic vibration milling device and tool were selected, then made a test of overall vibration characteristics. Though choosing the right milling variables to design experimental program, when did experimental study on the milling force by traditional milling or ultrasonic milling, Made a qualitative analysis the trends affecting of each milling parameters to milling force, using the regression methods to qualitative analysis milling force’s experience model on ultrasonic vibration millingWhen making a study about under different milling parameters and different processing surface roughness testing and microstructure observation of optical glass samples, the surface morphology of these samples were did a qualitative analysis by ultra- depth microscope, the surface roughness values of these samples were tested by white light interferometer. Research the trend about various milling parameters on surface roughness; combine with milling force experimental results, then analyze the influence about variation of milling force to surface roughness. Make use of the regression methods to qualitative analysis surface roughness’ s experience model on ultrasonic vibration milling; finally make an analysis between theoretical model of the surface roughness on ultrasonic vibration milling with experience model, to verify the accuracy and precision of this theoretical model.Optical glass was processed in ultrasonic vibrations milling, PCD tool morphology image were collected before and after processing by ultra- depth microscope, By comparison tool surface layer and the micro-level, make an analysis about the form and abrasion key positions of tool wear, then explore tool wear mechanism under ultrasonic milling, and put forward an improved method for reducing tool wear.