Investigation into effect of particle impact damping (PID) on surface topography in boring operation

This paper presents a novel method, based on the particle impact damping (PID), for the attenuation of regenerative vibration in boring operation. A specially designed boring bar having a cavity near machining-end for partial filling of spherical particles has been developed. Characteristics of boring bar with and without PID have been found from impact and shaker tests. After identifying appropriate particle size and filling volume, experiments are conducted to evaluate the performance in actual boring operations. Additional boring experiments are also conducted to confirm the performance by changing particle size and filling volumes. The collision of the particles in PID is found to attenuate regenerative vibration by the energy dissipation and thus effectively enhances stability of the boring operation. Analysis of effect of PID on surface topography in terms of chatter marks, surface roughness, and roundness of bored holes shows that the proposed method results in improvement of bore quality when compared with a boring bar without PID. It is also established that radial vibration of the boring bar has a significant influence on the surface topography obtained in boring operation.