An in-process tool wear evaluation approach for ultra-precision fly cutting

Ultra-precision fly cutting (UPFC) is an intermittent cutting process, which is widely used in the fabrication of non-rotational symmetric micro structures with sub-micron form accuracy and nanometric surface roughness. In UPFC, the occurrence of tool wear certainly affects the accuracy of machined micro structures. Aimed at the close relations between tool wear and chip morphologies and the truth that cutting chips are fully formed in a cutting cycle, this research developed a tool wear evaluation approach based on cutting chips. Chip morphology features related to tool failure patterns were identified and then parameterized to predict the tool failure patterns, the surface topography, and surface roughness under the effects of tool failure patterns. Predictions were then verified by experimental results. Research results show that chip morphologies were successfully used to present tool failure pattern, following the well-designed identification procedures, the tool failure patterns are accurately identified. This approach is practical since it can in-process identify tool failure patterns and their effects on surface quality.