Investigation of foamed cathode through-mask electrochemical micromachining developed for uniform texturing on metallic cylindrical surface

Abstract

Surface texturing with micro-dimples has been proved to be an effective approach in many fields to improve the functionalities and performances of some mechanical components. Through-mask electrochemical micromachining (TMEMM) is a popular technique to create textures on metallic surface, but it is still very challenging to be used to texture curved surface. In this paper, a novel TMEMM process was proposed to generate micro-dimple array on the cylindrical surface. In this TMEMM process, a foamed metal film with a good pliancy performance and a huge number of interconnected micropores is introduced to serve as the cathode, which is further integrated with the reusable through-mask and workpiece to form a sandwich-like assembly. The current distribution within each region being machined and its correlation with the geometric dimensions of through-hole, as well as with the relative location of the through-hole in the mask, are analyzed numerically. With this TMEMM process, a great number of micro-dimples with a good uniformity in their geometric dimensions can be produced both on the planar and the entire 360° cylindrical workpiece surfaces in only one operation, showing the minimum coefficient of variation of the dimple’s depth and diameter being 5.6 and 2.4%, respectively. The reasons for such a favorable result are interpreted theoretically. The proposed TMEMM process here could have a great potential in generating geometrically consistent surface textures on the curved surface efficiently and low-costly.