Modelling of the combined microstructural and cutting edge effects in ultraprecision machining

The mechanics of ultraprecision machining (UPM) is known to be affected by materials microstructures and cutting tool geometries when cutting magnitudes are reduced to micron-scale. To model the combined effects, a flow stress model that correlates the grain size and chip thickness to the relative tool sharpness is first proposed. Subsequently a novel behavioural chip formation model is developed to distinguish the transitions in chip formation regimes due to the microstructural and cutting edge effects. This led to the discovery of a unique finishing regime where surface roughness is improved by 61.7%, 63.9% and 86.4% for Al-alloy, Mg-alloy and Cu-alloy respectively.