Experimental study of a new micromilling process for vortex curved thin walls.

High-aspect-ratio vortex curved thin wall is widely used in electronics, precision instruments, aerospace, and other fields. It is a typical flexible geometrical structure with varying curvature making it very difficult to be fabricated with high quality due to burrs, dimensional errors, tool marks, and other defects in the machining process. In order to improve the machining quality of vortex curved thin walls, a new micromilling process with large cutting depth and slow feed is proposed. Firstly, through the single factor finite element simulation and micromilling experiment, the influences of radial depth of cut ae and feed per tooth fz on milling forces are analyzed under the condition of large axial depth of cut ap. Then, under the guidance from the results of single-factor experiments, the orthogonal experiments are conducted selecting surface roughness Ra, dimensional error △w, and burr height h as the evaluation indexes of machining quality. The influences of key milling parameters (feed per tooth fz, axial depth of cut ap, radial depth of cut ae, and spindle speed n) on machining quality are explored. By comprehensively analyzing the key milling parameters and their effects, an optimum combination of cutting parameters is identified. Finally, the new micromilling process is validated for the fabrication of high quality vortex curved thin walls. [ABSTRACT FROM AUTHOR]