Fundamental insights of mechanical polishing on polycrystalline Cu through molecular dynamics simulations

Abstract

Mechanical polishing is an ultra-precision class finishing process to achieve a nanoscale surface finish. During nano-polishing of any engineering materials, the material removal takes place in the form of atomic-clusters. However, quantifying the process characteristics becomes difficult from a mechanical and metallurgical point of view. To understand the mechanism of material removal on polycrystalline material during nano-polishing through abrasives, a molecular dynamics simulation has been implemented. This simulation work investigates nano-polishing on polycrystalline copper (p-Cu) with two different cases of abrasive sizes at different cutting velocities. Results were analysed for the temperature, percentage of material removal, shear slip planes, dislocations, and interaction forces between abrasive and p-Cu workmaterial. Increased abrasive sizes and velocities resulted in increasing interaction forces during nano-cutting until shear slip formation. The p-Cu grains adjacent to the abrasive undergoes different elastoplastic deformation due to the shear slip and sessile dislocations, which affected the surface finish. This work is helpful to utilize mechanical nano-polishing or diamond turning process parameters for efficient material removal from polycrystalline surface.