Vibration Control of Tool Flank Wear in Turning

Introduction . The wear rate of a cutting tool can be controlled by introducing additional vibrations into the cutting zone. The effect of vibration parameters on tool wear appears to be well-studied. However, the conclusions of some such studies are contradictory. It is noted that vibrations of varying amplitudes can both increase and decrease wear. There are no analytical models in the literature that resolve this contradiction or reflect the nonlinear relationship between the tool and workpiece subsystems under cutting. Furthermore, the fact that wear on different tool faces requires different force interaction models is not taken into account. The present research fills these gaps. The objective of the study is to determine the patterns of impact of high-frequency vibrations (HFV) on tool flank wear. Materials and Methods . The data from mathematical modeling of the dynamic cutting system in Simulink were used, taking into account the forces on the back face, effective parameters, and the HFV. Equipment: 16K20 machine tool, vibration control measuring stand with a frequency range of 0.4–15000 Hz, computer, E20-10 analog-to-digital converter, acoustic system, and STD.201-1 cutting force testing stand. Workpieces made of 10GN2MFA steel with a diameter of D = 84 mm were machined using tools with brazed T15K6 plates without lubrication. Results. The effect of the HFV on the contact interaction forces along the tool flank and the phase trajectory of the tool deformation displacements are demonstrated for different HFV amplitudes: from 0.5 ⋅ 10 –2 to 2 ⋅ 10 –2 mm. It is established that power N of irreversible energy transformations (IET) depends on the direction of the introduced vibrations. The dependence of tool wear rate on additional vibrations with amplitudes of 5 and 10 µm in different directions at cutting speeds of 1 m/s, 1.4 m/s, and 2 m/s is shown. The results obtained are compared with wear trajectories without disturbances. Discussion . The optimal amplitude of additional vibrations in the feed direction depends on the tool clearance and decreases with wear stage. The maximum wear value drops from 0.55 mm to 0.35 mm when introducing vibrations with an amplitude of 5 µm and to 0.26 mm — at 10 µm. With additional vibrations in the tangential direction, wear rate depends weakly on the amplitude of the introduced vibrations, as it is many times smaller than the velocity of the tool vibrational displacements. The maximum wear value decreases from 0.65 mm to 0.6 mm at 5 µm and to 0.48 mm — at 10 µm. With increased wear, there is no optimal amplitude for additional vibrations. Conclusion . The developed models allow for a quantitative assessment of the impact of HFV on the tool flank wear rate and the appropriate selection of vibration parameters introduced into the cutting zone. This allows for the creation of: virtual models of the cutting process and the selection of modes to minimize wear rate; wear monitoring systems with a comprehensive approach to prediction. Next, it is required to study the dynamics of the cutting process at HFV amplitudes greater than 10–15 µm.