OBRABOTKAMETALLOV Vol. 27 No. 1 2025 technology Fig. 5.Example of a graph showing the change in force components over cutting time during milling process along the growing direction (B = 2 mm, V = 16 m/min, t = 1 mm, fmin = 25 mm/min) Thus, we conclude that the identified irregularities in the cutting force characteristics are the result of manufacturing deviations made during the production of the milling cutter. These deviations likely involve imperfections in the tooth geometry or inaccuracies in their placement. At the same time, it can be stated that the installation and fixation of the milling cutter in the chuck are performed correctly and are not the cause of the observed phenomenon. A detailed study of the Ph force variation curve, which demonstrates a clear repeatability of peaks and valleys, confirms this conclusion, allowing further analysis to focus on the technological aspects of the tool manufacturing process. A more detailed analysis of the cutter geometry is necessary to determine the exact causes of these deviations from the ideal geometry and to assess their impact on the quality of machining and the dimensional accuracy of the resulting part. Analysis of the cutting force dynamics of Ph (see Fig. 4), which is the most informative and easily observable component of the force interaction, reveals approximately symmetrical patterns of its increase and decrease during conventional milling. This is somewhat contrary to the expected asymmetry, caused by a significantly shorter period of the tooth exiting the cutting zone compared to the period of its entry. Theoretically, a rapid decrease in the chip thickness before the tooth completely exits should lead to a steeper drop in the Ph force. This is explained by the change in the orientation of the force vector Pz as the tooth approaches the exit point. At the moment preceding the exit of the milling cutter tooth from the contact zone, Pz rotates in the direction of rotation of the milling cutter. This gives a more significant increase in the radial component of the force Pv than the force Ph. As a result, the decrease in the Ph force begins earlier — even before the main cutting edge completely leaves the contact zone with the workpiece. The presence of the cutting edge inclination angle, denoted as ω (or β in some foreign publications), plays a key role in the milling process. This angle prevents the entire cutting edge from simultaneously entering the contact zone with the workpiece or exiting it. Instead of an abrupt cessation of the cutting process, a more gradual process occurs. Individual sections of the cutting edge sequentially exit the interaction with the material. The milling width B and the inclination angle ω have a significant impact on the smoothness of the decrease in all components of the cutting force — axial Px, tangential Pz, and radial Py. The greater the values of these parameters, the smoother and less abrupt the decrease in cutting forces will be when the tooth exits the machining zone. This is explained by the fact that a wider tool and a larger inclination angle provide a more gradual change in the contact area between the tool and the workpiece. A more gradual decrease in cutting forces, in turn, leads to reduced vibrations and improved surface finish. However, the milling process, especially in conventional milling, involves a complex interaction of several factors. The rotary motion of the milling cutter, the changing orientation of the force vectors Pz and Py, and the simultaneous variation in chip thickness a result in a certain phase shift between the changes in forces. This shift manifests itself in the fact that the change in the radial force Py (lateral force Pv in Fig. 4) does not perfectly coincide in time with the change in the tangential force Pz (feed force Ph in Fig. 4). This phase shift, although slight, is a consequence of the dynamic processes occurring in the cutting
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