Fast texturing of micron grating on curved metallic surfaces using bending-torsional-coupled rotary ultrasonic side milling

Structural coloration by texturing micron gratings has been regarded as a promising approach for anticounterfeiting and functional decoration. However, the fabrication of micron gratings on curved surfaces is still challenging, restricting the application of structural colors. Taking advantage of the superior capacity of milling process in the machining of curved surfaces, this study proposes a novel texturing method for micron grating on curved surfaces by adopting bending-torsional-coupled rotary ultrasonic side milling (BTC-RUSM). The generation of gratings is governed by a "cutting and microforming combined process" in each vibration cycle induced by the bending-torsional-coupled vibration of the tool. The gratings with a spacing of 0.81 lm to 3.55 lm, controlled by the spindle rotation speed, are successfully fabricated. Structural coloration with colorful characters has been achieved on the curved surface. (c) 2024 Society of Manufacturing Engineers (SME). Published by Elsevier Ltd. All rights reserved.