Machinability Assessment of Aluminium Alloy EN AW-7075 T651 Under Varying Machining Conditions

This paper presents the experimental results of a study investigating the milling process of aluminium alloy EN AW-7075 T651. The main objective of the study was to establish the relationship between machining conditions, such as cutting parameters and cutting tool type, and selected machinability indicators, i.e. cutting force components and surface roughness parameters. The milling process was conducted using two different tools: a solid carbide cutter and a cutter with PCD (polycrystalline diamond) inserts. Obtained results showed that the use of the PCD tool led to a significant improvement of surface quality. In particular, the surface roughness parameter Ra was reduced, but changes are also visible for the other roughness parameters. Despite a similar trend of variations in surface roughness parameters observed for both tools, the values of these parameters obtained with the PCD tool were significantly lower. Similar values of the cutting force components were obtained with both cutting tools, these values being lower only in some cases for the carbide cutter. The effect of varying the cutting speed and feed per tooth on these indicators was also determined. The obtained results indicate that the selection of cutting parameters depends primarily on the expected results. Considering the surface roughness, it is better to use high cutting speeds, while in terms of cutting force, low speeds are more beneficial. In both cases, it is recommended to use the lowest possible feed.