Deformation and Microstructure in Machining

Deformation history and state of chip and machined surface in low-speed cutting have been characterized using image analysis, complemented by microstructure and hardness. Fine scale details of the deformation field of relevance to machining modelling are highlighted. The severe plastic deformation inherent to chip formation results in microstructure changes which can be controlled through appropriate process parameters selected with the aid of machining simulations. Scaling of subsurface strain distribution is observed. Similarity in deformation history of chip and near-surface suggests opportunities for engineering surfaces with controlled deformation levels and microstructures, directly, by machining. The deformation characterization offers substantial scope for improvement and validation of machining models, and enhancement of machining process capability.