Passive particle-impact damping for surface-quality improvement in end milling: Near active control efficiency

Surface quality is a key attribute in precision machining, directly influencing component performance and service life. Vibrations generated during cutting, particularly near resonant frequencies, strongly degrade surface finish and dimensional accuracy. This paper investigates the performance of a particle-impact damper (P-I damper) to improve surface flatness and roughness during end milling of thin-walled workpieces. A finite element model was coupled with MATLAB simulations to assess the dynamic performance of a workpiece equipped with the P-I damper absorber. The results show that the P-I damper is highly effective at reducing vibrations and enhancing surface quality. The flatness and roughness of the machined surface are significantly improved compared with the undamped case. Furthermore, the effectiveness of the P-I damper absorber in achieving the desired surface quality is quantified, and each block of the model is verified against published data. An active scheme is also investigated, in which the absorber is replaced by a bonded piezoelectric patch controlled by a collocated positive-position-feedback active-damping controller, which is fully controllable. Both strategies reduce regenerative chatter effectively (93.8% RMS reduction for the P-I damper against 97.1% for the active controller), though the active scheme is only marginally more effective. The particle-impact damper, however, does not require any power supply, sensing, or control electronics and is therefore much simpler to attach to the workpiece. The passive damper therefore provides near-active performance characteristics with the robustness and simplicity of a purely mechanical device, making it an attractive option for precision milling of flexible parts.