Simultaneous high-speed cutting and high-feed milling: An investigation on surface integrity

In this article, the potential of high-speed machining with an inverse cutting ratio b/h < 1 (uncut width of chip b to uncut chip thickness h) is presented based on the evaluation of surface integrity. If the machining is realized with a low cutting ratio many process quantities and chip formation mechanisms are fundamentally changed. As a result, the cutting process is stabilized through reduced feed forces and improved chip removal conditions. For the investigations, face-milling trials were carried out on an aluminum alloy (EN AC-42100) under conventional and high cutting speeds with variation of the feed per tooth and the use of cemented carbide and polycrystalline diamond tools. It is shown that when both machining strategies are combined, there is no further reduction in force components or improvement in surface topography. When the feed per tooth is increased at high cutting speeds, there is a linear increase in force components but surface roughness remain almost unchanged. After an initial increase in surface residual stresses, increasing the cutting speed leads mainly to compressive surface residual stresses. Overall, the surface integrity is influenced by the choice of cutting material and the micro-geometry of the cutting edge radius.