Investigation and optimization of parameters affecting surface roughness in single crystal copper nanomachining process using molecular dynamics method

Surface roughness is one of the most important features in nanoscale machining. Due to the use of nanometer-sized products for use in assemblies that require extremely high accuracy at a fraction of a nanometer, care must be taken in selecting machining parameters that affect the surface roughness. In this study, using molecular dynamics simulations, the machining of a single-crystal copper workpiece by diamond tools with different geometries has been investigated and the final surface roughness has been calculated. The effect of machining parameters such as cutting depth and cutting speed along with parameters related to tool geometry such as rake angle, relief angle and tip radius on surface roughness have been investigated with average roughness (R_a) and root mean square (RMS) measuring instruments. In order to study more precisely the effect of parameters and their interaction with each other, Taguchi method has been used to design experiments. The simulation results show that both the average roughness and root mean square parameters predict the greatest effect on the surface roughness of the workpiece due to the depth of cutting. Based on the presented results, it has been determined that the surface roughness can be improved in different machining conditions based on the selection of parameters, and it is necessary to carefully examine their conditions together before selecting these parameters. Using the Taguchi method, the optimal values of cutting parameters to achieve the best surface roughness in specified dimensions are described as