Influence of cutting fluid on machinability of optical glass SF6 during diamond cutting

This paper studies the machinability of optical glass SF6 in diamond cutting with sodium carbonate solution as cutting fluid. The indentation experiments on SF6 were conducted by using Vickers microhardness instrument, and then the change in hardness and toughness of SF6 were analyzed between pre- and post-immersion of the SF6 specimen in sodium carbonate solution. Then the scratching tests with increasing cut depth were performed, and the critical cut depth of SF6 was measured utilizing laser scanning confocal microscope. The experimental results indicate that, compared with scratching SF6 workpiece without cutting fluid, the value of critical cut depth increased by 35.6% with sodium carbonate solution as cutting fluid. Based on the results of the indentation and scratching experiments, turning tests were carried out. Compared with the dry cutting process, the surface roughness of SF6 workpiece decreased by over 50% with cutting fluid, which is verified by atomic force microscope(AFM). As a result of experimental evaluation, the machinability of optical glass SF6 can be improved by using sodium carbonate solution as cutting fluid.