“Nano-Pecking”: A Novel Ultrasonic Vibration Cutting Method for High-Efficiency Micro/Nano-Texturing

This study proposes a novel cutting method named “Nano-Pecking” for high-efficiency machining of high-precision functional surfaces with micro/nano textures, mainly V-grooves. Although Nano-Pecking can be categorized as ultrasonic vibration cutting, it has several unique features. The vibration direction and the tool are forward-inclined at an exceptionally large inclination angle so that the rake face is transferred to one side of the grooves while the cutting-edge locus is transferred to the other side. The grooves are formed in a direction parallel to the cutting edge, enabling high-efficiency texturing at large pick feeds. Another unique feature is that the actual cutting direction is more perpendicular than parallel to the workpiece surface, which is unusual in cutting. To understand this unique process, the thin shear plane model based on the minimum energy principle was applied to predict the shear angle and cutting forces. Nano-Pecking experiments were conducted on electroless Ni-P-plated workpieces, and reasonable agreement was confirmed between the predicted and measured shear angles and cutting forces. The model revealed that the actual depth of cut decreases with increasing actual shear angle, leading to an extraordinarily large shear angle. The functionality of the V-grooved surfaces was further evaluated experimentally. The V-grooved mold surfaces successfully reduced reflectance and enhanced hydrophobicity compared with a mirror-finished surface. These results demonstrate the feasibility of Nano-Pecking as an efficient micro/nano-texturing process.