Seen in the context of manufacturing machining processes, the ability to rough-grind glass, an essential!) brittle material, firstly to form, incurring considerable sub-surface damage, and then to free-abrasively polish it to nanometric roughness levels and micrometric form, is remarkable. Single-point studies of the fracture mechanics and machinability of glasses show that, at incursion levels of sub-micrometre order and forces of the order of grams, plastic deformation dominates material deformation processes. The implications of brittleness being scale-dependent are considerable embracing the possibilities for single-point machining.nWhereas it is difficult to experimentally observe the action of a single-particle among the many under a lap, observation and analysis of single-point machining may be usefully employed to explain lap-grit actions. Surface roughness values, damage-depths, interface presentation, limitations on inherent form-convergence and the role of statistical averaging in abrasion may be combined to provide a mechanical model for certain particulate actions.
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