Surface Workhardening and Residual Stresses Induced by Micro Cutting Processes

X-ray diffraction, optical microscopy and microhardness testing have been used to study properties which develop in micro-cut AISI 1045 steel. The influence of the ploughing effect on residual stresses, surface deformation and work hardening, and the tool quality were investigated. Tensile residual stresses, caused by the heat generated in the material during the cutting process, were observed in all investigated specimens. An increase of the ploughing effect resulted in higher residual tensile stresses at the surfaces of the specimens. The depth of plastic deformation created in the material by the micro-cutting process also increased with an increase of the ploughing effect. A gradient in the hardness of the material was observed after micro-cutting. A systematic study of the influence of the cutting tool edge radius revealed that additional processes inherent to the machining process, namely the build-up of new edges at the tool front, can significantly influence the results of the micro-cutting process.