Ultrasonic Cutting / Ul’trazvukovoe Rezanie / Ультpaзвyкoвoe peзннe

On the mechanism and mechanics of material removal in ultrasonic machining

“…The increase of static load induces greater chipping forces by each grain, which raises the material removal rate. However, in actual practice the machining rate first increases with static load and after reaching an optimum value, it falls with a further increase in static load [1]. The decrease in material removal rate at higher static loads is due to the fact that the removal of debris becomes more difficult as the tool is not allowed to vibrate properly.…”

“…is the main goal of USM manufacturers and users. The material removal rate obtained by this process is often acceptable for super-hard and brittle materials [1]. Although USM have been extensively used in industrial applications during the last two decades, however, the actual utilization has been quite limited mainly because of the difficulties involved in machining process and associated high cost of machining the materials by this process while ensuring the workpiece quality.…”

“…When the average grit size approaches the dimension of the gap, some of them with larger diameters will exceed the size of the gap and hence can not get into the cutting zone to participate in the machining process, which reduces the number of active abrasive particles in action. Rosenberg et al [1] made a statistical analysis of a number of abrasive powders and empirically determined the size distribution of grains as…”

“…To explain the nature of the USM, Shaw [2], Rozenberg et al [1] and Kainth et al [8] employed indentation fracture models. They assumed that each abrasive grit removes a hemispherical portion from the workpiece due to material fracture caused by indentation.…”

“…(ii) An individual grain has many tiny projections (act as cutting points) on its surface (also called local spherical bulges), therefore, for simplicity, these local spherical bulges, are approximated as hemi spheres of diameter ξ b , randomly distributed throughout the grain surface [1].…”