In internal turning of hardened steel carried out with cubic boron nitride (CBN) tools, the main concern is with the workpiece surface finishing, usually aiming to achieve a surface roughness similar to the attained in grinding processes along with gains in productivity. However, vibrations from the...

In internal turning of hardened steel carried out with cubic boron nitride (CBN) tools, the main concern is with the workpiece surface finishing, usually aiming to achieve a surface roughness similar to the attained in grinding processes along with gains in productivity. However, vibrations from the process often cause premature chipping in the tool and/or damage to the workpiece finishing. To minimize vibration, one solution is the use of passive and active dampers with different types of construction. Passive damper contrasts with active damper due to its low cost and simpler construction. The use of particle impact passive damper aided by compressed air to promote workpiece surface roughness reduction was studied. For this, different materials, particle size, packing ratio, and overhang boring bar were tested. Based on the results, it was possible to conclude that the airflow aided particle damper reduced the mean surface roughness by around 60% compared to non-airflow damping in 120 mm (L/D = 6) boring bar overhang

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