Reduction of tool wear during hydrodynamic polishing: A ‘rock-and-roll’ polishing strategy

In this paper, a ‘rock-and-roll’ polishing strategy is proposed for reducing the influence of tool wear on machining rates during hydrodynamic polishing. An analytical study suggests that the radius of curvature of spherical tools changes rapidly during the tool wear process. In addition, variations in the tool radius have a significant effect on machining rates. Increasing the contact length of the tool rapidly decreases the variation in the toolʹs radius of curvature. A rock-and-roll polishing strategy is therefore proposed to increase the contact length of the tool. This strategy is proposed to design the toolʹs rocking motion with an appropriate dwelling-time distribution so as to increase the area (or contact length) of the wear zone and create a uniform wear depth, which will in turn reduce the variation in the tool radius. A separate volume removing analysis of the tool wear suggests that the dwelling time of a tool at a given position can be determined for a given wear depth and wear rate. Finally, an experimental study confirms that the proposed strategy can reduce the variation in the toolʹs radius of curvature and that the effect of tool wear on the machining rate can be suppressed.