A numerical study of cutting edge radius effects on stress evolutions of diamond coated tools

The stress state of a diamond coated tool is interrelatedly influenced by coating and subsequent machining. Moreover, the cutting edge geometry strongly impacts the stress fields around the tool tip in both processes. In this study, finite element modelling and cutting simulations were applied to investigate stress evolutions in a coated tool from deposition to machining, with the edge radius effect emphasised. For the deposition residual stress, edge sharpness results in significant stress concentrations at the edge rounding area. In machining, the thermal load is more dominant to the stress evolutions than the mechanical load. Increasing the edge radius generally results in increased stress reversal. Moreover, the edge hone effects on stress reversal are more prominent at a small uncut chip thickness. Since the edge radius has conflicting effects on the deposition stresses and machining loads, there may exist an optimal edge radius for the tool stress conditions.