During the micromachining of hardened materials, the low stiffness of the milling tool results in an increased tool deflection which has a great influence on the shape and dimensional accuracy of the machined components. In order to compensate these deflections, an optimization method is presented in this paper. Based on measured form errors of the machined workpieces, the NC programs are optimized iteratively to reduce the shape deviations. To verify this method, experimental investigations were carried out by milling pockets in hardened steel. The results show a significant reduction of the tool deflection after the optimization.

In a production of filigree and complex geometries, different NC-controlled processes such as laser cutting, EDM milling, and micromachining require a constant feed rate to ensure high-quality manufacturing results. Due to the technically limited acceleration ability of the machine tool axes, the nominal feed cannot always be achieved. This in particular is the case when the machine tool has to perform a significant change of direction in corners. In this paper, the impact of too low feed rates on the process of precise micromilling of a hardened high-speed steel AISI (M3:2) 63 ± 1 HRC) is discussed. An unattained feed rate leads to a ploughing dominated process with a high burr formation resulting in a huge potential loss of micromilling processes. Furthermore, a simulation approach is presented which allows the prediction of the actually achieved feed rate. The developed machine model provides a reliable method to identify critical areas in the entire NC program.