Molecular dynamics simulations of plastic material deformation in machining with a round cutting edge

This paper reviews the application of the molecular dynamics simulation approach to the high-resolution visualization of the plastic material flow at the tool/workpiece interface during orthogonal cutting. MD simulation techniques have been applied to nano-scale processes, but due to restrictions in the model size and computational time, they have not been utilized to investigate processes occurring at the micro-scale. Techniques employed to extend the MD simulation techniques to the micro-scale are discussed. Preferred ranges for model parameters that provide for sufficient resolution in order to adequately describe the characteristic features of the plastic material flow, yet achieve significant reduction in the model computational times, are identified. An investigation of the plastic material flow at the tool/workpiece interface as the uncut chip thickness increases from 10% to 90% of the edge radius of the tool was undertaken. A key observation is that there is a marked variation in the geometry of the observed characteristic features, most notable being the rotation and growth of the stable built-up edge as the uncut chip thickness increases. Furthermore, the transition between the plowing and cutting regimes is observed.