Micro Dimple Milling for Structured Surface

Abstract

A micro dimple machining is presented to control the surface functions with the micro-scale structures on the solid surfaces. The micro dimples are machined in milling with the inclined ball end mill. When an inclined two flutes end mill removes the material in a depth of cut less than the tool radius, the air cutting time during neither edges contact with the workpiece appears in a rotation of cutter. When the tool is fed at a high feed rate so that the removal areas of an edge and another edge do not overlap each other, the concave dimples are machined. A mechanistic model is presented to control the shape and the size of the dimples to be machined. The micro dimples were machined to verify the mechanistic model in milling. The micro asperities were also formed in molding using the dimpled surface. As applications of the functional surfaces, wettability and friction coefficient were measured on the surfaces with the dimples and the asperities. The surface functions change with the alignments of the dimples and the asperities.