Position-Driven Nanosurface Generation in Diamond End-Flycutting

In diamond cutting, the uniformity of residual tool marks (RTMs) is crucial for analyzing optical surface quality. Previous studies have typically assumed that RTMs have a spatially uniform height under ideal cutting conditions. This work revisits this assumption by revealing and mathematically characterizing the inherent position-dependent nonuniformity of RTM heights in diamond end-flycutting. Kinematic modeling and experimental verification demonstrate that end-flycutting using a round-nose diamond tool inherently produces a nonuniform surface morphology, characterized by higher RTMs near the trajectory center and lower RTMs toward the edge region. This finding necessitates a reconstruction of theoretical frameworks for surface prediction, establishing workpiece position as a fundamental, yet previously overlooked, process parameter. Experiments show that the machined surface roughness varies with position, with the edge region exhibiting lower surface roughness than the central region. This study provides novel insights for optimizing end-flycutting parameters in ultraprecision machining.