An analysis method for atomistic abrasion simulations featuring rough surfaces and multiple abrasive particles

Nanotribological simulations of multi-grit polishing and grinding

“…2). An analysis of the drift velocity histograms and a study of the crystallographic order in the defined zones, as discussed in further detail in [4], justify this approach. The applicability of the chosen identification scheme can also be illustrated using the drift velocity map of one of the simulated systems (see Fig.…”

“…The total number of atoms remains constant throughout a simulation run, and periodic boundary conditions are applied in the lateral directions so that an atom that exits the simulation box to one side re-enters it from the opposing one. As explained in detail in [4], the difference between the modelling of the polishing and grinding processes is that in the polishing process, the grits are restricted to the spherical geometry, may roll across the surface and have the possibility of avoiding topographic obstacles by moving in the y direction, which is orthogonal to the sliding motion. They may also adjust their z-position individually as would be the case in a polishing slurry.…”

“…For a comprehensive account of how the model was set up, how the periodic Gaussian surface topography was produced, and which computational constraints were imposed, the reader is referred to previous work by the authors [4]. Fig.…”

“…The authors have recently proposed a modelling and analysis approach based on MD [4] which can be applied to simulations of nano-scale polishing and grinding. While polishing and grinding are generally considered processes featuring mechanisms occurring mainly at the micrometer-scale, where the grain structure of the work piece material plays an important role, this work focuses on phenomena which take place at an even smaller length scale.…”

“…Our entire model system can thus be seen as part of a single grain within a larger work piece, and the mechanisms involved in material removal at this scale do not include the breaking out of entire grains but rather exhibit atom-by-atom desorption and subsequent formation of debris. Our computational scheme laid out in [4] features the correct generation of atomistic surfaces with pseudo-random Gaussian roughness which satisfy periodic boundary conditions, dynamic wear particle and contact zone identification, a clustering algorithm to evaluate individual abrasive contributions to the wear volume and contact area, as well as grid-based topography analysis. While this approach is open to extension in many ways (e.g., multi-grain substrates, larger systems in terms of lateral substrate dimensions, as well as size, surface coverage, explicit bonding, and wear of the abrasive particles), our present work exploits the possibilities employing a basic model on a purely atomistic scale with a homogeneous material.…”