Characterization of tool-workpiece contact during the micromachining of conductive materials

The characterization of dynamic cutting in micro-machining operations is essential for real-time monitoring of tool performance. The analysis of tool-edge/material contact and its electrical resistivity is therefore an interesting avenue of research for monitoring tool-workpiece interaction. This study examines mechanical cutting operations in micromilling operations that remove material to meet the design requirements of conductive parts. It draws from previous research into the theoretical models of cutting mechanisms in milling operations, to present a mathematical characterization of the tool-edge/material contact area. The rationale behind this research is that the contact area between two conductive materials is one of the main factors in determining the magnitude of resistance to the flow of an electric current between both materials. The study also offers a theoretical analysis of tool-edge radial immersion angles on entry and exit and their dynamic behavior. The analysis is mainly centered on cutting operations and cutting-time intervals, where tool-material contact is intermittent. Our theoretical analysis is experimentally corroborated by measuring tool-edge immersion time and tool-edge/material contact time. Promising results are reported that contribute to the development of a technological method for high-precision, real-time monitoring of tool-workpiece interaction and cutting detection in micromachining operations.