Precision machining of brittle materials has until recently been primarily conducted by grinding and polishing due to excessive tool wear and surface fracture in traditional processes. In 1991, Moriwaki and Shamoto1 introduced vibration-assisted machining of stainless steel, a process whereby a single point tool is vibrated at frequencies as high as forty kilohertz. This process reportedly reduces friction and therefore cutting force, extending tool life and significantly improving surface finish. The variations of this technique allow for the vibration directions to include the cutting direction, the thrust direction, and the feed direction. For ultrasonic vibration-assisted diamond turning, typical frequencies of tool tip vibrations are on the order of forty kilohertz and amplitudes are up to fifteen micrometers. These severe requirements have limited the previous designs to mechanical resonator systems with fixed operating frequencies and amplitudes due to excessive heat generation in piezoelectric actuators and limitations of system mechanical dynamics.
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