Dynamic stress propagation induced transition of stress state and microstructure characteristics during high-speed cutting of OFHC copper

摘要

High-speed cutting (HSC) is a popular technique applied in manufacturing as it can significantly improve machining efficiency and surface quality. However, when the cutting speed is increased to extremely high, the deformation process of the material will be changed due to the alteration of microstructures and loading conditions; as a result, some deeper understandings of the mechanisms are still required. In this study, a dislocation density-based constitutive model is implemented to describe the material behavior of OFHC (oxygen-free high conductivity) copper during high-speed cutting process, which is then used to obtain the characteristics of dynamic stress propagation through physical parameters of the material, so that the relationship between dynamic stress propagation and microstructure evolution can be directly described. The results show that the propagation of plastic deformation will be significantly changed when cutting speed is increased to extremely high, and the transformation of stress states between loading and unloading will lead to the change of gradient distribution of strains and microstructures. This research can be used to understand the stress state variation during dynamic deformation in the cutting process through microstructure characterization in future investigations.