Investigation on Machining Performance of Amplitude Control Sculpturing Method in Elliptical Vibration Cutting

The authors have proposed a unique micro/nano sculpturing technology for difficult-to-cut materials by controlling vibration amplitude in elliptical vibration cutting. In the present research, machining performance of the amplitude control sculpturing method is investigated, and limitation in nano-scale machining is explored. In the proposed machining method, the machinable part geometry is essentially restricted by cutting tool geometry and vibration conditions. In order to clarify the machining performance of the proposed technology, a series of analytical and experimental investigations were conducted. From the experimental results, it was confirmed that nano structures with a step height of more than 2 nm and a pitch of more than 250 nm can be machined with surprisingly high accuracy of about 1 nm. On the other hand, a considerable error between the amplitude command and the envelope of tool trajectory is generated when the slope of the machining part geometry becomes large. In order to overcome this error, a compensation method of the amplitude command is proposed. By applying the proposed compensation, nano structures with large ratio of the step height to the pitch were machined accurately. The proposed machining method was subsequently applied to a three-dimensional grid surface machining, and successful experimental results verified feasibility of practical machining application by applying proposed technology.