Surface defects during microcutting

Surface microdefects such as dimples are always found on machined 1045 steel surfaces as a result of the dual phase microstructure of the workpiece material. Finite element (FE) analysis on dimple and chip formation showed similar trends to those acquired experimentally. The formation of dimples at grain boundaries is explained by considering the plastic dissipation energy inside of individual grains in the material microstructure during microscale cutting. Dimples are shown to occur at a hard-soft grain boundary in the direction of cutting, but never at a soft-hard grain boundary.