Fabrication and mechanism analysis of wavy fins using a novel machining method

Abstract

This research proposed a novel plowing extrusion-cutting (PE-C) method for efficiently fabricating 3D functional fins with novel wavy-shaped structures, which could be applied for electronics cooling, chemical reaction, and other energy applications. PE-C sequentially involved three critical stages: preheating, plowing extrusion (PE), and cutting. During PE, the preheated metal was adequately shaped into grooved structures. The cutting stage was the core procedure for the whole PE-C, in which grooved structures were multi-folded into arrays of wavy fins. Comprehensive experiments were conducted to investigate the forming performance of PE-C. Subsequently, an in-depth comparative analysis was performed to clarify their forming mechanism and geometric model. Results show that the tool rake angle γc, cutting velocity Vc, and relative cutting thickness tpd were critical parameters to control wavy fins' geometry (shape and size). Small γc, Vc, and tpd contributed to fabricating wavy fins with large amplitude As, while the period width Pw of wavy fins remained basically stable under variable parameters. During the cutting stage, the forming process of the fin top and its bottom had a velocity difference due to the different stacking deformation. Accordingly, the established geometric model showed good agreement with the experimental results. In addition, PE-C could be applied in conventional rough-cutting procedures to reduce waste chips. Therefore, PE-C was a feasible and efficient process for direct fabricating geometrically advanced fins instead of waste chips during machining, exhibiting great potential in fabricating 3D fins and recycling chips.