Fabrication of structurally colored basso-relievo with modulated elliptical vibration texturing

Abstract

Elliptical vibration texturing is a newly arising method for the fast and cost-effective generation of near-subwavelength micro-structures on metal surfaces. This study proposes a fabrication method for structurally colored basso-relievo by combining the surface sculpturing and elliptical vibration texturing in one-step machining. Synergistic modulations of both nominal cutting speed and depth-of-cut (DOC) in elliptical vibration texturing are applied to provide concave-convex topography and structural coloration. A new rendering strategy for the face turning configuration with an equidistant spiral tool path has been presented to improve the image rendering efficiency over the raster scan tool path. In addition, different from the conventional elliptical vibration texturing, the nominal DOC dynamically changes pixel by pixel in the proposed new process. In order to identify the effects of DOC and elliptical vibration trajectories on the surface quality and fidelity of generated gratings, grooving experiments have been conducted on brass samples to further the understanding of nonlinear tool-workpiece interactions. Finally, both raster scan and face turning tests have been performed on an ultraprecision platform with optimized process parameters. Structurally colored basso-relievos with high quality have been successfully demonstrated using the proposed fabrication method.