Fundamental study of nano-scale machining using bubble raft model

Abstract

The bubble raft model has been employed to investigate the cutting mechanism in nano-scale machining. The present paper first describes the instrumentation and measurement, then examines the influence of cutting conditions and tool geometry on chip formation and subsurface damage. Damage caused by edge dislocations increases with increasing depth of cut, or tool edge radius, or both. Atomistic defects, including vacancies and grain boundaries initially induced into the model, cause the damage to develop. These phenomena have been successfully visualized by means of the behaviour of soap bubbles. The experimental results are compared with those obtained by the molecular dynamics simulation of orthogonal machining of a copper single crystal. Qualitative agreement between the bubble raft model and the MD simulation can be seen with respect to basic cutting phenomena including chip formation and subsurface damage, in which a similar deformation mechanism through dislocations plays a primary role. Interaction between tool and workpiece is also a key factor in nano-scale machining.