The mechanism of bright and dark strip visual defects on side milling surfaces induced by loss-cutting

With the advancement of machining technology, surface visual defects have emerged as a new aspect of surface quality concerns, alongside geometric features and physical-mechanical properties. However, the mechanism behind these visual defects remains unclear. Focusing on bright and dark stripes which is a typical visual defect observed in the side milling process of 3C workpieces, the paper investigates its causes, manifestations, and criteria. Initially, the loss-cutting is identified through analysis of surface profiles during vibration between the workpiece and cutting tool. Subsequent discussion investigates the impact of loss-cutting on surface markings. Furthermore, the study examines surface visual characteristics affected by loss-cutting, utilizing insights into human eye perception. Analysis of causes and manifestations of visual defects in bright and dark stripes follows. Criteria related to working conditions, including spindle speed , feed rate, cutting tool tooth count, and vibration frequency , are then proposed. Finally, experimental validation is conducted. This research bridges gaps in understanding the mechanism and assessment methods of visual defects in surface quality systems, laying groundwork for tracing and controlling such defects. • The loss-cutting induced by the relative vibration between the cutting tool and workpiece is found for the first time. • The causes and manifestations of visual defects in bright and dark stripes resulting from loss-cutting are analyzed. • The criteria of visual defect in bright and dark stripes related to the parameters of working conditions are proposed.