Molecular Dynamics Modeling of Nano-grinding Process of Copper Alloy with a Rotational Tool

Abrasive processes are essential for obtaining a high-quality surface on mechanical parts after the main features have been created through subtractive or additive manufacturing processes. Especially, in cases when ultra-high-quality finishing is required, nanometric level accuracy should be achieved using appropriate methods. To investigate the fundamental mechanisms of abrasive processes at the nanometric level, a Molecular Dynamics model for nano-grinding of copper alloy is developed. This model uses a novel rotational nano-grinding tool, composed of multiple grains which are positioned on the circumference of the tool tip and simulations under variable process conditions, such as rotational speed, and grinding depth are carried out to identify the contribution of each parameter to the outcome of the nano-grinding process and to determine optimum nano-grinding strategies. By analyzing the results of the simulations concerning nano-grinding forces, temperature and subsurface alterations, considerable insight into the mechanisms of nanometric grinding processes is obtained. The results indicated that both grinding depth and rotational speed affect the process with the former leading to a moderate increase of grinding force and temperature while the increase of latter leads to a clear decrease of grinding forces within the selected range. Finally, both parameters contribute to superficial and subsurface alterations, mainly by changing the removed material volume dimensions and extent of amorphous structure regions.