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 a e and feed per tooth f z on milling forces are analyzed under the condition of large axial depth of cut a p . Then, under the guidance from the results of single-factor experiments, the orthogonal experiments are conducted selecting surface roughness R a , dimensional error △ w , and burr height h as the evaluation indexes of machining quality. The influences of key milling parameters (feed per tooth f z , axial depth of cut a p , radial depth of cut a e , 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.