Investigation of the Effect of End Mill-Geometry on Roughness and Surface Strain-Hardening of Aluminum Alloy AA6082.

Micro-milling is a promising technology for micro-manufacturing of high-tech components. A deep understanding of the micro-milling process is necessary since a simple downscaling from conventional milling is impossible. In this study, the effect of the mill geometry and feed per tooth on roughness and indentation hardness of micro-machined AA6082 surfaces is analyzed. A solid carbide (SC) single-tooth end-mill (cutting edge radius 670 nm) is compared to a monocrystalline diamond (MD) end-mill (cutting edge radius 17 nm). Feed per tooth was varied by 3 μm, 8 μm and 14 μm. The machined surface roughness was analyzed microscopically, while surface strain-hardening was determined using an indentation procedure with multiple partial unload cycles. No significant feed per tooth influence on surface roughness or mechanical properties was observed within the chosen range. Tools' cutting edge roughness is demonstrated to be the main factor influencing the surface roughness. The SC-tool machined surfaces had an average