Molecular dynamics study on the influence of surface texture on nanopolishing process and subsurface damage of single-crystal tungsten

As a critical strategic material for extreme environment applications, the surface integrity of single-crystal tungsten directly dictates the performance and reliability of functional devices. However, the damage evolution mechanisms of single-crystal tungsten during nanopolishing manufacturing processes have yet to be systematically explored. In this study, molecular dynamics simulations of nanopolishing were established to specifically investigate the mechanical properties, crystal defect evolution, and subsurface damage mechanisms under various initial surface roughness conditions at the nanoscale. The results reveal that surface roughness texture, acting as a key geometric constraint for material removal mechanisms, exerts a significant influence on atomic migration, cutting load fluctuations, and the distribution of subsurface stress fields. Meanwhile, the internal energy dissipation and dislocation density within the system exhibit trends of dynamic growth and non-linear oscillation. Furthermore, variations in the structural complexity of the surface texture lead to distinct shifts in the temperature rise patterns within the processing zone. This research elucidates the nanopolishing mechanisms induced by surface morphology from an atomic perspective, providing essential theoretical criteria and technical guidance for achieving high-efficiency and low-damage ultra-precision manufacturing of single-crystal tungsten.