Study On Nano Edge-radius Micro-tools Fabrication And Nanocutting Mechanism

Precision and ultra-precision machining is one of the most important technology in manufacturing. This capability directly influences the industry development. As a new technology developed in second half of the twentieth century, the ultra-precision cutting has the advantage of getting an ultra-smooth surface directly, which can be used to improve the production efficiency, the machining accuracy and surface quality. With the material removal gradually reduced, the conventional machining mechanism is unable to explain the mechanism of material removal in the nanometer scale. The minimum thickness of cut indicates the highest cutting precision capacity, and it is the most powerful manifestation in ultra-precision machining.This dissertation will focus on the nano edge-radius micro-tools fabrication and nanocutting mechanism curried out with the sharp micro-tools:Focused ion beam was used to fabricate diamond cutting tools with nanometer edge radius. By the combination of the theoretical analysis and experimental optimization, the diamond cutting tools with edge radius less than 20 nm was successfully fabricated. Based on the self-developed multi-DOF nanofabrication platform, the asymmetric structure milling tools were fabricated with more rational structure and overall strength.In the micro tool preparation process, the amorphous layer thickness on diamond surface directly affects the tool performance and life. Based on the laser micro-Raman spectrometer, a method using Raman ratio for measuring nanoscale amorphous layer thickness was presented. The analysis error is less than 3nm when the amorphous layer on the diamond surface is less than 50 nm.The diamond tool with nano edge radius was used to study the nanocutting mechanism and the controllable chip thickness of less than 5.9 nm was achieved on a single-crystal copper. At the same time, it was confirmed that when the tool cutting edge radius and cutting depth were both in nanometer scale, the chips were formed by extrusion rather than shearing.