Research On Wet Chemical Mechanical Grinding And Its Tools For K9 Optical Glass

K9 optical glass has stable physical and chemical properties, especially the excellent optical processing performance, making it widely used in the fields of optical instruments and high-grade crafts. The glass surface precision affects the performance of the instrument directly.Because of its hard and brittle properties, it is extremely difficult to obtain high quality surface by using traditional processing methods. In this paper, the Chemical Mechanical Grinding (CMG) in wet environment is investigated to arrive high surface precision for K9 optical glass processing.First, the abrasives workmanship was researched. Dry CMG tests were conducted according to the characteristics of K9 optical glass later. The surface roughness of the K9 optical glass was measured by the 3D surface profiler. The mass of the K9 sample were contrasted by using the precision electronic balance before and after the test to calculate the Material Removal Rate (MRR). The deionized water spray created by ultrasonic atomization method was applied to form a wet environment. Balancing the test results in dry and wet environment, the abrasive formula were adjusted. And the alkaline of the wet environment were controlled by adding the appropriate amount of NaHC03. The CMG tests under different alkaline environment were carried out using the adjusted formula’s abrasives. The orthogonal test of multi factor including spray alkaline, workpiece speed and grinding speed were carried out to study the effect on the performance. The results show that the best result occurred with the condition of the worse alkaline spray, grinding speed of 600r/min and the workpiece speed of 250r/min. The minimum surface roughness can reach Ra 0.515nm, the maximum material removal rate is 95.37nm/min. The influence degree of grinding parameters on the surface roughness are the spray PH, abrasive speed and workpiece speed respectively,while the influence degree of grinding parameters on the material removal rate are the spray PH, workpiece speed and abrasive speed respectively.The surface of K9 optical glass after the wet CMG displays perfect with no scratches and other defects observed by the Metallographic microscope. Using X ray diffraction (XRD) to detect the debris under the moist environment, there are new compounds appeared, which verified the chemical reaction during the grinding process. Finally, the material removal mechanism of the wet CMG on K9 optical glass was put forward.