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

Abstract

<jats:p>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 m , 8 m and 14 m . 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 R q = 119 nm, while the MD-tool machined surfaces reached R q = 26 nm. Surface strain-hardening is influenced mainly by the cutting edge radius (size-effect). For surfaces produced with the SC-tool, depth of the strain-hardened zone is higher than 200 nm and the hardness increases up to 160% compared to bulk. MD-tool produced a thinner strain-hardened zone of max. 60 nm while the hardness increased up to 125% at the surface. These findings are especially important for the high-precision manufacturing of measurement technology modules for the terahertz range.</jats:p>

Effect of Tool Coating and Cutting Parameters on Surface Roughness and Burr Formation during Micromilling of Inconel 718

“…Jan C. Aurich et al [73] focused on the tilt angle of the spindle speed to increase the machining quality during the micromachining process and concluded that the tilt angle of the spindle speed decreased both surface roughness and burr formation. Pavel Filippov et al [74] investigated the effect of tool geometry on surface roughness and strain hardening during micromilling of aluminum alloy. It was concluded that the tool with a higher cutting-edge radius (r) produced a high surface roughness and large depth of strain hardening zone, whereas smaller r produced a low surface roughness and low depth of strain hardening zone.…”

Feasibility of Cobalt-Free Nanostructured WC Cutting Inserts for Machining of a TiC/Fe Composite

“…The cutting edge radius of the WolCar insert was 12 μm, while in the typical edge of the WC-Co insert BK6 (with 6 wt.%Co) it is 28 μm [ 23 ]. It is widely recognized that the cutting tool geometry has an effect primarily on surface roughness [ 24 ], but in addition, some authors indicate its influence on the intensity and course of dynamic load [ 25 ]. In our study, the machined surface of the TiC/Fe composite after cutting with WolCar inserts exhibited much higher quality and surface integrity than that after BK6 inserts.…”